UNITED STATES DISTRICT COURT

NORTHERN DISTRICT OF FLORIDA

PENSACOLA DIVISION

IN RE: 3M COMBAT ARMS ) Case No. 3:19md2885

EARPLUG PRODUCTS LIABILITY )

LITIGATION )

) Judge M. Casey Rodgers

This Document Relates to All Actions ) Magistrate Judge Gary R. Jones

ADOPTION OF PLAINTIFF’S PRIOR GENERAL EXPERT REPORT

RICHARD L. McKINLEY

ORIGINALLY SERVED OCTOBER 9, 2020

November 20, 2020

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UNITED STATES DISTRICT COURT

NORTHERN DISTRICT OF FLORIDA

PENSACOLA DIVISION

IN RE: 3M COMBAT ARMS )

EARPLUG PRODUCTS LIABILITY )

LITIGATION )

 )

)

This Document Relates to All Actions )

Case No. 3:19-md-2885

Hon. Judge M. Casey Rodgers

Magistrate Judge Gary R. Jones

Rule 26 Case Specific Expert Report of Richard L. McKinley

I. QUALIFICATIONS

I am a Biomedical Engineer and Acoustics SME with expertise in assessing the impact of noise in 

warfighting operations. I earned my Bachelor of Science in Biomedical Engineering from 

Vanderbilt University in 1975 and my Master of Science in Communications/Signal Processing 

from the Air Force Institute of Technology in 1986.

In 1976, I began my career in bioacoustics at Air Force Research Laboratory (AFRL) at WrightPatterson Air Force Base, Ohio, where I worked as a government civilian until I retired in June of 

2016. Since then I have worked as a part-time contractor support AFRL and the F-35 Joint 

Program office. During my tenure at AFRL, and as Principal Acoustics Engineer for the 711 

Human Performance Wing, Human Effectiveness (directorate) and lead of the Air Force 

Battlespace Acoustics program, I led the development of high-performance hearing protection, 

establishment of noise exposure criteria, measurement of intense noise fields, enhancement of 

voice communication performance, and development of 3-D auditory displays. 

Among the achievements and breakthroughs accomplished during my tenure, AFRL created the 

world's first practical ANR headset, the first synthetic 3-D audio display, the first working direct 

fiber-optic microphone, and the first successfully demonstrated active noise cancellation of 

external aircraft flyover noise. The expansiveness of my involvement in Department of Defense 

acoustics-based work included my role as branch senior scientific advisor and lead of the joint 

AF/Navy team formed to address F-35 noise issues. Today, I remain one of the world’s top experts 

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for assessing the impact of noise to all warfighting operations. While at AFRL, I conducted 

numerous measurements to assess the performance of hearing protectors, including REAT, MIRE, 

and Impulsive Noise measurements. I also conducted statistical analyses in accordance with 

ANSI/ASA S12.6- 2008 (formerly ANSI S3.19-1974); ANSI/ASA S12.42-2010; and ANSI/ASA 

S12.68-2007. AFRL was also asked to perform testing on hearing protectors, at various times, by 

other branches of the Armed Services. This testing included testing linear and non-linear ear plugs, 

including the Combat Arms Version 2.0 (“CAEv2”) that is the subject of the present litigation. 

As to these and other testing standards, I was an active voting member on the ASA/ANSI working 

group that developed and oversaw ANSI 12.6, 12.42, and S12.68. I also represented the United 

States Air Force on three ASA/ANSI accredited standards committees, S1, Acoustics, S3, 

Bioacoustics, and S12 Noise and currently chair four standards working groups: S1/WG4 

Measurement of sound pressure levels in air; S1/WG15 Noise cancelling microphones; S3/WG94 

Localization standards; and S12/WG53 High performance aircraft noise measurement. I am an 

approved/voted individual expert on S1, S3, and S12 accredited standards committees that oversee 

numerous working groups responsible for developing standards in acoustics. Following my career 

at AFRL, I have worked under contract as an F-35 Senior Acoustics SME.

I hold several leadership and honorary positions in professional organizations and societies within 

my discipline. In 1996, I was elected Fellow of the Acoustical Society of America. In 2010, I was 

selected as an AFRL Fellow in recognition of my substantial contributions in the critical area of 

bioacoustics in the fields of noise effects and human auditory information processing.1 This 

designation is reserved for the top 0.3% of AFRL scientists and engineers. Along the way, I have 

had the honor of working with fellow hearing conservationists and acoustics and auditory human 

factors scientists. I have authored over 150 publications in acoustics and noise. Additionally, I 

have held several Chair positions in ANSI Working Groups throughout my career.

 1 Nelson, Todd (2010). “Senior Scientific Advisor Earns Fellow Standing.” Wright-Patterson AFB. 

https://www.wpafb.af.mil/News/Article-Display/Article/400002/senior-scientific-advisor-earns-fellow-standing/. 

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During my career I have published broadly in the area of bioacoustics. Notable publications 

include the following:

• Gallagher, H.L., Bjorn, V.S., and McKinley, R. L., Attenuation performance of double 

hearing protection devices, Acoustical Society of America, POMA Volume 11, pp. 

040005 (August 2011).

• James, S.H., et al, Hearing Protection – Needs, Technologies and Performance, NATO 

Technical Report, RTO-TR-HFM-147, Nov 2010.

• Hall, J.A., McKinley, R.L., New Directions for Custom Earplugs, Proceedings Internoise 

2005, Aug, 2005.

• Simpson, B. D., Bolia, R. S., McKinley, R. L., and Brungart, D. S., The impact of hearing 

protection on sound localization and orienting behavior. Human Factors, 47(1), 188-198.

2005.

• Nixon, C.W., McKinley, R.L. and Steuver, J.W., "Performance of Active Noise 

Reduction Headsets," Basic and Applied Aspects of Noise-Induced Hearing Loss, Dancer, 

Salvi, Henderson, and Hammernik, editors, Mosby Yearbook, 1990.

As an expert in the area of bioacoustics, I have presented papers on the topics of acoustic emissions 

from F-35A and F-35B aircraft and performance assessment of passive HPD for the American 

Institute of Aeronautics and Astronautics (AIAA) and AFRL, respectively. I have also presented 

my work on methods for measurement of noise emissions from high performance military jet 

aircraft at the National Conference on Noise Control Engineering.

I have received numerous awards and honors throughout my career. Most recently, I and several 

of my DoD colleagues received the Department of Defense (DoD) Standardization Program 

Award (MILSTD 1474E Noise Limits) in 2015. In 2014 I was a member of a team that received 

the AFRL 711th Human Performance Wing Scientific and Technical Achievement Award. My 

other awards and other achievements are detailed in my curriculum vitae, attached as Exhibit “A.”

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II. INTRODUCTION

Permanent hearing loss in the military is a condition that is preventable, yet 14% of veterans 

discharged from active duty after serving in Iraq and Afghanistan have been diagnosed with 

defined hearing loss.2 During active duty, hearing loss is a significant factor in loss of awareness 

of acoustic events, loss of communication capability (particularly in low to moderate noise 

environments3

), and loss of ability to detect quiet sounds (especially those at high frequencies). 

These losses can disqualify Service Members from certain job functions, including leadership 

positions commanding or directing tactical warfare or piloting an aircraft. Upon discharge, 

veterans with permanent hearing loss, tinnitus and other auditory issues to include hyperacusis will 

continue to suffer. Among the few options available, some veterans are prescribed hearing aids.4

Unlike losses in visual acuity that can be mitigated with corrective lenses, hearing loss is more 

analogous to macular degeneration. Hearing aids do not correct for loss of hearing sensitivity. 

They are more like a magnifying glass to a person with macular degeneration. Hearing loss and 

tinnitus can also cause interpersonal problems both at work and home.5 The human toll in quality 

of life relative to communicating with others, enjoying the soundscape of a national park, locating 

sound sources such as a car before crossing a street, and so on and so forth, are significant. 

My lifelong goal, along with my colleagues in the Department of Defense and other government 

agencies such as the US EPA and NIOSH, has been to reduce and prevent duty related noise 

induced hearing loss in military and civilian service members.

 2 Swan, A.A., et al. (2017). “Prevalence of hearing loss and tinnitus in Iraq and Afghanistan Veterans: A chronic 

effects of neurotrauma consortium study.” Hearing Research, vol. 349, p.4-12. 3 Suter, A. The Ability of Mildly Hearing-Impaired Individuals to Discriminate Speech In Noise. Joint EPA/USAF 

Study. January 1978 (established foundational understanding of challenges faced by individuals with hearing loss 

experiencing difficulty with word discrimination with background noise particularly with frequencies greater than 

2000 Hz, focusing in on the “speech-to-noise ration” component of speech discrimination). 4 For more on prescribing hearing aids, see Theodoroff, Sarah M., et al. (2015). “Hearing impairment and tinnitus: 

Prevalence, risk factors, and outcomes in US service members and veterans deployed to the Iraq and Afghanistan 

wars.” Epidemiologic Reviews, p.1-5; and Yankaskas, Kurt D., and Jeffrey M. Komrower (2019). “Military and 

industrial performance: The critical role of noise controls.” International Journal of Audiology, vol. 58, no. 51, 

p.574-580. 5 For more on this, see Casali, John G., et al. (2009). “A field investigation of hearing protection and hearing 

enhancement in one device: For soldiers whose ears and lives depend upon it.” Noise & Health, vol. 11, no. 42, 

p.69-90; Yong, Jenica Su-ern, and De-Yun Wang (2015). “Impact of noise on hearing in the military.” Military 

Medical Research, volume 2, no. 6, p.1-6; and Vannson, Nicolas, et al. (2015). “Quality of Life and Auditory 

Performance in Adults with Asymmetric Hearing Loss.” Audiology & Neurotology, vol. 20, p.38-43.

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III. ASSIGNMENT

I was retained by the Plaintiffs Steering Committee in In re: 3M Combat Arms Earplug Prods. 

Liab. Litig. (3:19-md-02885) to evaluate available facts, evidence, literature, documents, and other 

source information in furtherance of understanding the CAEv2 and providing my expert opinion 

on whether the CAEv2’s risks, if any, outweighed its benefits. My analysis included a review of 

the design files and historical documents relating to the original ISL filter, the stem and adapter 

component part, and the two pre-existing plugs used for the dual-ended design sold to the military 

between 1999 and 2015. 

I evaluated internal 3M/Aearo and 3M (collectively, “3M”) documents as well as other literature 

and secondary sources. The latter included peer reviewed literature and testing data from the 

Department of Defense, Department of Energy, French-German Research Institute of Saint-Louis 

(ISL), and other national, international, and outside laboratories. My evaluation considered 

whether the CAEv2’s design promoted and achieved initial fit and seal, as well as continued seal 

and whether the CAEv2’s design provided proper and necessary noise attenuation and impulsive 

noise insertion loss (IPIL). 

Finally, I considered whether 3M/Aearo satisfied certain requirements under the Medical 

Procurement Item Description (MPID) 2003, revised 2006, as follows: 

− As to 2003 and 2006 MPIDs regarding testing, sampling for inspection at 100% on 

the nonlinear yellow end to be “verified by an acoustical impedance test”6

; 

− As to 2006 MPID regarding testing and efficacy, sampling for inspection of the 

linear green end under ANSI/ASQ Z1.4 (inspection level S-2) with AQL of 1.0%; 

and

− As to 2006 MPID regarding efficacy, that the CAEv2 would provide the “user” 

with “protection” at sound pressure levels up to 190 dBP, even after the user has 

been exposed to 100 free-field noise impulses of 190 dBP, minimum. 

I am being compensated for my time at a rate of $400.00 per hour.

IV. STATEMENT OF OPINIONS

Based on my education, experience, research, review, evaluation and analysis, I believe the 

following design defects were substantial contributing factors to auditory injuries sustained by 

 6 I understand that 3M was required under MPID 2003 and 2006 to retain all “records of inspection” for a period of 

3 years after delivery of the earplugs, including 3M/Aearo subsidiary or sub-contractor TJR/ATM, and that records 

relating to impedance testing and quality control were not made available potentially due to 2-year retention policy. 

For MPID 2003’s records policy, see DOD Touhy Production Document Touhy00000952. For MPID 2006’s 

record’s policy, see 3M_MDL000002017. For 3M’s destruction of its quality records for the CAEv2, see Childress 

30(b)6 Tr. 152:17-155:20 and 263:14-23. 

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users of the CAEv2 and that these defects present an unreasonable risk of auditory injury to the 

users. My opinions are based upon a reasonable degree of scientific probability:

Opinion #1: The CAEv2 was defectively designed in that it contained an inflexible, hard, barbed 

and wide adapter assembly which was positioned deep within the flanged tips thereby preventing 

users from achieving a proper fit, seal and/or cause imperceptible loosening compromising 

continued seal. 

Opinion #2: The CAEv2 was defectively designed because opposing flanges were too close to the 

inserted flanges which precluded users from achieving a proper fit, seal and/or cause imperceptible 

loosening compromising continued seal. 

Opinion #3: The CAEv2 was defectively designed because the ISL filter, stem and adapter 

assembly were placed in a manner and location creating a significant, unintended and harmful 

standing resonance at high frequencies. 

Opinion #4: In addition to these design defect opinions, I have the following opinion with regard 

to their compliance which the terms of the MPID:

1. 3M/Aearo failed to provide accurate quality assurance verification by an acoustical 

impedance test for all CAEv2 it sold on the nonlinear end as required by the 2003 and 2006 

MPIDs.

2. 3M/Aearo made no effort to provide quality assurance in any manner, much less an 

acceptable REAT measurement on a required sample size, to ensure the quality of the linear 

end as required by the 2006 MPID.

3. 3M/Aearo made no effort to determine, much less verify, that the CAEv2 could provide 

users with protection at sound pressure levels up to 190 dBP, even after users had been 

exposed to 100 free-field noise impulses of 190 dBP, minimum. The Blast Overpressure 

Studies relied upon to make this assertion fail to provide a reasonable basis upon which to 

make such an assertion relating to the CAEv2. 

V. STATEMENT OF ADDITIONAL OPINIONS

1. The manufacturer’s REAT testing under ANSI S3.19 (“213015”) documented in the 

“Flange Report” revealed unacceptable variability in attenuation for the CAEv2. The 

Standard deviation calculations in the 213015 study were consistently high across all tested

frequencies, including extreme variability at low and high frequencies, resulting in the 

experimenter and 3M/Aearo lead scientists to internally document this variability and loss 

of acoustical seal.

2. Aearo’s experimenter observed variability and minimal or loss of attenuation which is due 

to unintended acoustical leak. There were no documented tears, rips, or other physical 

explanations for an acoustical leak. Based on Aearo’s Test 213015 results, it is reasonable 

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to conclude that the plug’s design results in an unacceptable variability7 across subjects as 

to attenuation characteristics, seen across multiple frequencies (including higher 

frequencies that is more uncommon). This placed 3M/Aearo on notice that there were 

design characteristics that should have been discussed and evaluated prior to proceeding 

with an adjusted ANSI 3.19 with flange roll-back. Significant variability in fit and seal will 

increase the likelihood that users will unwittingly suffer acoustic leaks, rendering the plug 

insufficient to provide expected attenuation. 

3. The documentation relating to the design characteristics of the CAEv2 adequately support 

a reasonable conclusion that the CAEv2 is defective in design to include those I recite in 

my Summary of Opinions and Expert Report. 

4. The CAEv2 contains a hard, plastic adapter stem connecting the linear and nonlinear ends, 

housing a filter providing nonlinearity protection for impulsive noise. The connecting 

adaptor has a diameter too wide and placed too deep into the ear canal, the widest barbed 

component part seated within the third flange in both directions. Reviewing the design 

drawings and related materials, it is reasonable to conclude that the width, shape and depth 

of the adaptor piece is incongruent with the human inner ear resulting in fit, seal and 

continued seal issues subjecting the plug to imperceptible loosening. 

5. The loosening potential is exaggerated by the manufacturer’s chosen material Delrin which 

is an inflexible plastic. The thin rubber stems and flanges of the plugs are not thick enough 

or soft enough to absorb these forces resulting in the expulsion force being applied more 

directly on the hard-plastic adaptor stem, resulting in a loosening effect on the plug. 

6. The manufacturer had available designs and stem materials available, along with ANSI 

S3.19 Testing on plug tips, which would likely have improved fit and seal, minimized the 

potential for accelerated extended wear loosening, provided optimal attenuation and would 

provide a user with a safer and more effective protector. These include:

a. Positioning the adapter stem more shallow in the plug;

b. Using a stem configuration similar to those used in earlier (French/CAEv1) and 

later iterations of the CAE product line and/or competitor products; 

c. Using a shorter adapter stem as used in later CAE versions;

d. Using a more flexible material like that used in the Ultraflex Semi-Aural Insert 

device, which used plug tips nearly identical to the green end of the plug, but used 

more flexible insert adapter stems, and the Ultrafit Plus, which used an identical tip 

to the Green End, yet achieved a higher NRR during ANSI S3.19 Testing. 

e. Designing the adapter stem with features that resulted in less contact with the inner 

ear canal, and less hard edges for forces to push against resulting in loosening forces 

being applied.

 7 In review of Dr. Dave Eddins’ Report, statistical analysis was performed relating to Test 213015 (flanges not 

rolled back), 213017 (flanges rolled back) and other testing which reveal a statistically significant rate in the 

differences in attenuation of the CAEv2 from Test 214015 and intra-lab tests performed by Aearo/3M establishing 

variability which should have raised concerns and may have led to the abrupt termination of the REAT test at 8 

subjects.

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7. The CAEv2’s design has opposing flanges that, when inserted, may contact the user’s outer 

ear anatomy, including the tragus, anti-tragus and cochlea, creating deformation of the 

flanges. 

8. Difficulty with proper initial fit and seal, as well as continued seal, would be expected. 

9. After insertion, the opposing flanges, based on their well-understood material properties 

and physical characteristics, will attempt to retain their original shape, and exert 

longitudinal forces against the wearer’s outer ear anatomy. In agreement with Newton’s 

third law of motion, where every force has an equal and opposite force, it is reasonable to 

expect such user will suffer a “pulling effect” on the entire plug away from the aperture 

resulting in loosening of the plug. 

10. The characteristics of a user’s inner ear and outer ear determine the nature of the push out 

and pull out forces applied to the plug based on its design characteristics. These effects are 

described in the “Flange Report”.

11. Complicating matters further, it is reasonable to conclude that the protrusion of more than 

half (50%) of the CAEv2 outside of the aperture of the user’s ear would have created a 

toggle or fulcrum effect by which forces were exerted, particularly under physical 

movement conditions, that added to the loosening effect caused by defects which were 

already causing push-out and pull-out in users.8 

12. Taken together, it is reasonable to conclude that the CAEv2 suffered from both a defect in 

design relating to the adapter stem and opposing flanges which, independently and/or 

collectively, caused users to gain proper fit and seal, continued seal, and caused 

imperceptible loosening of the plug, decreasing attenuation and protection from hazardous 

noise.

13. The data received from Test 213015 should have raised concerns regarding the design 

choices that had been made for the CAEv2. 

14. 3M/Aearo should have drawn upon significant experience in designing and testing the very 

plug tips used in the CAEv2 when confronted with the poor outcome of Test 213015. 

15. The manufacturer developed and tested predecessor plugs (UltraFlex/UltraFit Plus and 

UltraFit) with satisfactory attenuation. However, when those tips were combined to make 

the CAEv2 and Test 21305 revealed very poor attenuation and high variability, revealing 

fit and seal concerns during testing phases, the manufacturer should have re-designed the 

plug instead of changing the insertion technique to gain a higher noise reduction rating. 

16. The manufacturer, further, understood the importance of (and promised) a quality testing 

program to assure the yellow level-dependent end of the plug would provide the insertion 

loss required for impulsive noise for users. An Acoustic Resistance Checker (ARC), the 

test was considered critical in determining efficacy yet the government appears to have 

been never apprised of serious problems with the testing setup, process and procedure, 

 8 As described in Section IV of the Report of Eric Rose (Aearo/3M failed to account for the effect of moving the center 

of gravity outward with the design of the dual-ended CAEv2 compared to the single ended combat arms plug shifting). 

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input/output data, presence and prevalence of out of specification results, provision of 

waivers and other information to make a judgment as to the quality of ear protector the 

government was receiving. 

17. Documents and testimony relating to quality testing program reveal significant problems 

with the testing devices and plugs testing well out of quality specification ranges. This 

appeared to occur whether the ARC boxes were purportedly properly calibrated, miscalibrated, or uncalibrated; and whether the testing occurred in Mexico or Indianapolis. 

18. At one point, over 80% of plugs were reported as having tested out of specification, 

however, there is no documentation revealing that the government was made aware.

19. Plug dimensions which can alter ARC results are likewise critical in a user’s protection 

from hazardous noise. 

20. Based on a review of the noise propagation through the CAEv2, as supported by test 

outputs from IPIL testing done on the CAEv2, a problematic resonance appears. It is 

reasonable to expect that this frequency would cause an unintended risk to the user at high 

frequencies. Resonance observations in testing demonstrate that the filters design and 

positioning was suboptimal and constituted a design failing. 

21. The manufacturer was obligated to test the linear end of the CAEv2 for attenuation under 

ANSI Z1.4 which if failed to do. 

22. Assurances made to the government that the CAEv2 would provide the user with protection 

for up to 100 rounds, free-field, at 190 dBP was never tested or substantiated.

I hold these opinions to a reasonable degree of scientific certainty. Further, I have reviewed the 

Expert Reports issued by Dave Eddins, Steve Armstrong, Eric Rose and Dave Madigan and find 

that the results in those Reports are consistent with my opinions.

VI. INTRODUCTION

1. HEARING CONSERVATION IN THE MILITARY

a. Brief History of Military Hearing Conservation Program Lineage

Innovations in military aeronautics and propulsion, including advent of the jet engine in the late 

1940s, introduced hazardous noise sources that gave rise to additional efforts to protect service

members from acoustic injuries. These efforts culminated in the creation of hearing conservation 

programs within the Department of Defense starting with the Air Force (1948) and followed by 

the Navy (1955)9 and Army (1956). The Air Force undertook a leadership role in advancing 

hearing conservation in the military by being the first to issue mandatory hearing conservation 

measures. Thereafter, each of these services revised their hearing conservation program guidelines 

 9 Bohnker, Bruce K., et al. (2002). “U.S. Navy and Marine Corps hearing conservation program, 1995-1999: Mean 

hearing thresholds for enlisted personnel by gender and age groups.” Military Medicine, vol. 167, no. 2, p.132.

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to comply with the 1978 DoD Instruction (Department of the Navy, 1979; Department of the 

Army, 1980; Department of the Air Force, 1982). 

Additional changes included an updated hearing conservation program instruction promulgated as 

6055.12 (DoD, 1987). DoD mandated that uniformed services comply with OSHA regulations, 

but military standards and criteria were actually more stringent.10 For example, the DoD regulation 

exposure criterion for continuous noise is 85 dBA, while the OSHA criterion is 90 dBA for an 8-

hour day. Additionally, OSHA uses a 5 dB per doubling exchange rate (i.e., 95 dBA would be 

allowed for 4 hours), while the DoD uses a 3 dB per doubling exchange rate (i.e., 88 dBA would 

be allowed for 4 hours). Major components of military hearing conservation programs are directed 

towards reducing negative effects of noise on servicemembers and include noise exposure 

monitoring, engineering and administrative controls, audiometric evaluation, use of hearing 

protection devices, education and motivation, record keeping, and program evaluation.11 Although 

the minimum requirements set forth by the DoD instruction 6055.12 applies to all branches within 

the Armed Services, the same allows each branch to develop specific regulations.12

b. Army Hearing Conservation Program13

The U.S. Army has its own hearing program, which is outlined in Department of the Army 

Pamphlet 40-501, “Medical Services – Hearing Conservation Program” (DA-PAM 40-501). DODI 

6055.12, the Army published Technical Bulletin, Medical (TB MED) 501. This document was in 

response to DODI 6055.12 and was updated in 1987 to implement new requirements by the 1983 

Federal Noise Amendment. The new policy identified specific roles and responsibilities within a 

hearing conservation program and thereby paved the way for the first enforceable regulation to be 

 10 See Nixon, Charles W. (1998). “A glimpse of history: The origin of hearing conservation was in the military?” 

United States Air Force Research Laboratory, report AFRL-HE-WP-SR-1998-0005. 11 Centers for Disease Control and Prevention. In: Franks JR, Stephenson MR, Merry CJ, eds. Preventing 

Occupational Hearing Loss: A Practical Guide. Cincinnati, OH: National Institute for Occupational Safety and 

Health; 1996.

12 See AFI 48-20 Occupational Noise and Hearing Conservation Program, revised to AFI 48-127 (2016); DA PAM 

40-501 - Army Hearing Program); MCO 6260.3 Series - Marine Corps Hearing Conservation Program; 

OPNAVINST 5100.19 Series - Hearing Conservation (Afloat); and OPNAVINST 5100.23 Series - Hearing 

Conservation (Shore).

13 To aid the Court and Jury, I provide an additional section briefly outlining some important aspects of the Army 

Hearing Conservation Program understanding that initial trials focus on Army veterans.

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published on the subject. Revised in 1998, and most recently in 201514, other controlling 

documents were issued during interim periods, including Special Text Number 4-02.501, “Army 

Hearing Program” (“ST 4-02.501”)(2008).15 The Army HCP “protects the employee from hearing 

loss due to occupational noise exposure.”16 DA-PAM 40-501 lays out the requirements for 

implementing the HCP, the responsibility for which is delegated to the command level. Every 

installation level commander is responsible for appointing an Audiologist or another individual 

from the occupational medicine staff to act as the Hearing Conservation Program Manager 

(HCPM), who in turn is responsible for implementing the HCP as outlined in the pamphlet.17 The 

Army HCP also requires the following important action items:

• industrial hygienists are to take accurate measurements of the peak sound pressure levels 

and TWA of noise exposed personnel in all suspected noise hazardous areas, such 

measurements to be re-assessed yearly18;

• all personnel exposed to steady state noise at a TWA of at least 85 dB or impulse noises of 

140 dBP and greater are monitored19;

• Industrial hygienists to engineer controls to reduce harmful noises20;

• all personnel, working in or visiting noise hazardous areas must have HPDs with them at 

all times21;

• In line with DoDI 6055.1, personnel have a right to choose the HPD they prefer, “unless 

their selection is medically contraindicated or inappropriate for a particular noisehazardous environment.”22

• Requirements for HPDs in continuous noise are as follows:

o From 85 dB TWA to 108 dBA TWA, single hearing protection

o From 103 dB TWA to 108 dB TWA, double hearing protection23

• adopts the requirements for impulse noise set out in MIL-STD-1474D, which are as 

follows:

o From 140 dBP to 165 dBP, personnel must wear hearing protection

o From 165 dBP but less than or equal to curve Z, personnel must wear double 

hearing protection

o Exposure above curve Z require approval from the Surgeon General of the Army24 

 14 Medical Services - Hearing Conservation Program (DAP 40-501) (1998) and Army Hearing Program (DAP 40-

501) (2015). 

15 Army Hearing Program ST 4-02.501 (2008). 16 DA-PAM 40-501 (1998) at p.8. 17 Id. at p.6 18 Id. at p.9

19 Id. at p.9 20 Id. at p.6 21 Id. at p.8 22 Id. at p.10 23 Id. at p.10 24 Id. at p.29.

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c. Military Specific Noise Environments and Exposure

The military environment includes a broad range of noise sources, which can generate exposures 

which may be in excess of an equivalent level of 85 dBA over 8 hours.25 Noise sources may be 

hazardous to our Service Members depending upon, among other things: the noise source; the 

nature of the acoustic wave forms being emitted; the intensity or level of the noise or sound; and 

the duration of the noise or sound. Relative proximity to a noise source will affect the level of the 

sound which reaches a Service Member. Environmental factors may also increase or decrease 

noise propagation, including sound attenuation caused by reflection over ground26, surface or 

barrier absorption, acoustic shadows caused by waveform diffraction, and increases in noise 

exposure caused by reverberation. Additionally, accumulation of noise dose occurs as the levels 

integrated over the exposure times. In the Army, soldiers may be exposed to stead state or 

continuous noise in excess of 85 dBA for extended periods of time.27 Additionally, Service 

Members may also be exposed to impulsive noise in excess of 140 dB, a level determined to mark 

a peak decibel level above which a soldier without hearing protection is at potential risk of auditory 

injury.

 25 Yong, Jenica Su-ern, and De-Yun Wang (2015). “Impact of noise on hearing in the military.” Military Medical 

Research vol. 2, no. 6, p.1. 26 Wiener, Francis W., and David N. Keast (1959). “Experimental Study of the Propagation of Sound Over Ground.” 

Journal of the Acoustical Society of America, vol. 31, p.724. 27 TG250, Army Readiness through Hearing Loss Prevention (2014). US Army Public Health Command at p.3.

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Figure 1: TG250, Army Readiness through Hearing Loss Prevention, US Army Public Health 

Command, July 2014

The noise level reference chart shows both continuous noise levels and impulsive noise levels. 

The DoD’s hazardous noise exposure limits are a level of 85 dBA for 8 hours, or the equivalent 

level. Exposures above this level or its equivalent must be mitigated by hearing protection or 

reducing the exposure level and/or time. As reflected in the above noise level reference chart, 

almost every weapon used by the military generates impulsive noises over 140 dB. 

Though some Military Occupational Specialties (MOS) are potentially more likely to place an 

Army soldier at increased exposure to either hazardous steady state, impulsive noise or both, a 

preponderance of auditory injury for Army personnel occurs due to impulsive noise sources during 

training exercises. During peacetime, exposure to impulsive noises above occurs in training which 

also includes annual weapons qualification on the range. Though noises generated by military 

operations are potentially hazardous, the hazard can be mitigated through the appropriate use of 

effective hearing protection and application of the principles of hearing conservation, including 

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evaluation and noise abatement efforts by industrial hygiene. Conventional hearing protection 

devices can provide acceptable, safe protection in military environments.28

2. Principals of Industrial Hygiene 

Industrial hygiene is the science of anticipating, recognizing, evaluating, and controlling 

workplace conditions that may cause injury or illness. The Environment, Safety, and Occupational 

Health (ESOH) Community is sponsored by the Office of the Deputy Under Secretary of Defense 

(Installations and Environment) and the DoD Acquisition ESOH Integrated Product Team. This 

ESOH Community supplements DoD-level policy in DoDI 5000.02, Operation of the Defense 

Acquisition System, and guidance in the Defense Acquisition Guidebook and provides best 

practices and resources on how to integrate ESOH considerations into the systems engineering and 

acquisition processes. The acquisition Program Manager (PM) is required to prevent hazards 

where possible and manage their associated ESOH risks where hazards cannot be eliminated as 

part of the acquisition program’s overall cost, schedule, and performance risk reduction. The DoD 

employs ESOH risk management during system acquisition and sustainment to provide our 

warfighters the best equipment possible for executing its mission requirements of national 

defense.29 In the Army, personal protective equipment (PPE) is turned to when engineering or 

administrative controls are not feasible. Personal protective equipment can be used to protect 

individuals. PPE is utilized only when hazards cannot be eliminated or reduced with engineering 

and administrative controls as demonstrated by the Hierarchy of Controls30 as shown in the figure 

below.

 28 Casali, J., Berger, E. (1996). “Technology Advancements in Hearing Protection Circa 1995: Active Noise 

Reduction, Frequency Amplitude-Sensitivity, and Uniform Attenuation.” American Industrial Hygiene Association 

Journal, vol. 57, no. 2, p.175-85.

29 “Welcome to Our Community” (n.d.). Acquisition Community Connection, Environment Safety, and 

Occupational Health (ESOH). https://www.dau.edu/cop/esoh/SitePages/About.aspx. 30 “Personal protective equipment” (2019), Army Publish Health Center (APHC). 

https://phc.amedd.army.mil/topics/workplacehealth/ih/Pages/Personal-Protective-Equipment.aspx. 

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Figure 2 “Personal protective equipment” (2019), APHC. 

The Army Public Health Center provides significant information on Army health issues. The 

website has a page “Hearing Readiness and Conservation.”31 “The Army Hearing Program (AHP) 

provides information on hearing, hearing loss prevention, hearing protection, DOEHRS-HC, 

hearing monitoring, and reducing noise hazards. The AHP consists of four components: Hearing 

Readiness, Operational Hearing Services, Clinical Hearing Services, and Hearing Conservation.” 

a. Impulsive Noise as a Risk for Acoustic Injury

Impulse noise presents a special challenge for hearing conservation. Permanent hearing loss can 

occur from a single high intensity impulse or from exposure during weapons qualification on range 

while wearing inadequate hearing protection. Accurately assessing the hearing damage risk and 

associated noise doses for both short and long duration impulses is important for controlling the 

noise exposures to conserve hearing sensitivity. For situations such as a firing range, analyses can 

be conducted to establish the allowable number rounds to be fired based on the type of weapon 

being fired while taking into account other firing on the range, positions, hearing protection, and 

the other factors that affect noise exposure. Sounds or noises encountered in the military are often 

broad band and cover a wide frequency range for continuous noises. The damage from over 

exposure to broad band continuous noise usually begins in the 2-4 kHz range and spreads both 

upward and downward in frequency as the loss grows over time. Impulsive noises typically have 

a unique rise time and duration and can generate energy in higher or lower frequency ranges 

dependent on the duration. The long duration impulses such as those generated by artillery and 

 31 “Hearing Readiness and Conservation” (2019). Army Public Health Center (AHPC). 

https://phc.amedd.army.mil/topics/workplacehealth/hrc/Pages/default.aspx. 

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mortar firing as well as shoulder launch missiles and IEDs typically generate more low frequency 

energy. The shorter duration impulses associated with small arms firing generate more high 

frequency energy and therefore can be more damaging, for equal level impulses, than the long 

duration impulses.

b. Effect of Air Leaks in Ear Plugs

Air leaks may arise when earplugs fail to seal properly in the ear canal.32 All hearing protectors 

require an air-tight seal and must fit the ear canal perfectly to block sound from reaching the inner 

ear.33 If flanges fail to adequately seal to the ear canal walls then the dominant transmission path 

will be through the leak(s) around the flange. This is true even if the flanges form a patent seal 

further into the ear canal.34 Poorly fit protectors have low REAT attenuations and may provide 

only a few decibels of protection against high-level impulses.35 A slit leak may provide little or no 

attenuation in continuous noise environments of 80 to 120 dB SPL.36 A significantly loose earplug 

which has lost its seal may in fact cause resonance or amplification of noise amounting to an 

additional loss of attenuation in the low to middle frequencies.37 With respect to insertion loss 

measurements for impulsive noise, leaks introduced by an experimenter using a miniature 

microphone inside the occluded ear canal can show dramatically reduced insertion loss.38

c. Noise Induced Hearing Loss and Tinnitus

 32 3M_MDL000774997 33 Berger, E. (2011). “Custom Hearing Protection Have It Your Way . . . Maybe.” Industrial Hygiene News. 34 Murphy, William, and Elliott Berger (2006). “Results of the National Institute for Occupational Safety and Health 

Administration / Environmental Protection Agency (NIOSH/EPA) interlaboratory comparison of American National 

Standards Institute 812.6-1997 Methods A and B.”. The Journal of the Acoustical Society of America, vol. 125, no. 

5, p.1-22. 35 See Royster JD. et al. (1996). “Development of a new standard laboratory protocol for estimating the field 

attenuation of hearing protection devices. Part I. Research of Working Group 11 Accredited Standards Committee 

S12 Noise.” Journal of the Acoustical Society of America, vol. 99, p.1506-1526. See also Murphy William J., and 

Randy L. Tubbs (2007). “Assessment of noise exposure for indoor and outdoor firing ranges.” Journal of 

Occupational and Environmental Hygiene, vol. 4, no. 9, p.688-697; and Murphy, William J., et al. (2009). “An 

analysis of the blast overpressure study data comparing three exposure criteria.” Survey Report EPHB 309-05H. 

National Institute for Occupational Safety and Health. Cincinnati, OH.

36 Murphy, William J., et al. (2014). “Measurement of impulse peak insertion loss for four hearing protection 

devices in field conditions.” International Journal of Audiology, vol. 51, no. 01, p.1-30. 37 See 3M_MDL000371548 38 See 3M_MDL000335736 at p.58 and 3M_MDL000322632. 

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Both hearing loss and tinnitus are known injuries associated with exposure to noise hazards among 

our military who served in Iraq and Afghanistan.39 When a soldier is exposed to noise beyond 

well-established noise limits, the damage can be temporary or permanent and can occur in multiple 

ways, including metabolic fatigue of the hair cells and supporting structures in the cochlea or 

mechanical damage to auditory structures. These structures include the tympanic membrane, 

middle ear ossicles and cochlear anatomy (including the basilar membrane and outer steriocilia). 

Tinnitus may occur independent of hearing loss that is determined by audiogram, described by 

Packer et al. as within auditory dysfunction.40 Typically, metabolic fatigue related hearing loss, is 

due to continuous noises. Common continuous noise sources in the military include: vehicles; 

engines and helicopters. However, metabolic fatigue related hearing loss may also occur due to 

over exposure to sequential small arms fire, such as automatic weapons or firing on a range for 

qualification or training where multiple personnel are firing nearly simultaneously. These types of 

environments can cause metabolic stress, especially if the attenuation of the hearing protector is 

inadequate for the noise levels and exposure times. At high intensities, typically with large 

impulses, the mechanical mechanisms of hearing loss can become more prevalent and acoustic 

trauma and/or hearing loss from a single event or series of events.41

3. MILITARY NOISE EXPOSURE STANDARDS AND CRITERIA

The DoD and service hearing conservation programs define the noise exposure criteria for both 

continuous and impulsive noises. These criteria along with the noise attenuation of hearing 

protectors are used in assessing noise doses in an effort to eliminate over exposure and therefore 

reduce/minimize service-related noise induced hearing loss. In the military environment, 

reduction of noise levels and associated noise exposures through the use of engineering controls 

is usually an impractical solution. Hazard probability levels and risk assessment matrix, as referred 

to in MIL STD 882E and the Army’s TG351A (vol. 1-acoustic energy), are metrics utilized to 

determine and quantify noise hazardous sources and environment. The recent Army Hearing 

 39 Swan, A.A., et al. (2017). “Prevalence of hearing loss and tinnitus in Iraq and Afghanistan Veterans: A chronic 

effects of neurotrauma consortium study.” Hearing Research, vol. 349, p.4-12. 40 Id. 41 Rabinowitz, Peter M. (2000). “Noise-Induced Hearing Loss.” American Family Physician, vol. 61, no. 9, p.2749. 

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Memo “Interim Impulse Noise Damage Risk Criterion” outlines the Army’s shift from MIL STD 

1474E to a form of MIL STD 1474D.42 The criterion carries over all MIL STD 1474E basic 

impulse noise measurement requirements while also utilizing the AHAAH model. The Army 

Research Laboratory (ARL) of Aberdeen Proving Ground is a proponent of AHAAH, though 

Army Aeromedical Laboratory (USAARL) of Fort Rucker has tested and published its findings 

that AHAAH is premised upon unproven methodologies.43 General consensus within DOD and 

academia supports LAeq,8h or LAeq,100ms.44 This includes not only the Air Force and 

Navy/Marines, but also US allies including France and NATO.45 However, based on defective 

characteristics of CAEv2 described herein, the plug contained unique characteristics that 

significantly reduced the allowable number of rounds that a soldier could be subjected to thereby 

exceeding the limit recommended under any of the current standards referenced.

a. History and Evolution of Standards to Assess Hazards for Auditory Injury

At the request of the DoD, the National Academy of Sciences – National Research Council (NASNRC) established a special committee to respond to questions and issues dealing with human 

exposure to noise. The committee was called the NAS-NRC Armed Services Committee on 

Hearing, Bioacoustics, and Biomechanics (CHABA). The committee was jointly organized by the 

three services in December 1952. CHABA undertook to consider a number of factors and 

challenges in addressing the newly recognized noise hazardous conditions near and around jet 

engines, including: the effects and controls of noise; auditory discrimination; speech 

communication; fundamental mechanisms of hearing; and auditory standards.46

1) Development of Damage Risk Criteria for Impulsive Noise

 42 See Amrein, Bruce E., and Tomaz Letowski (2012). “High level impulse sounds and human hearing: Standards, 

physiology, quantification.” Army Research Laboratory, report ARL-TR-6017. 43 Id. 44 Id. 45 Id. 46 See Chaillet, Robert F., et al. (1964). “High-intensity impulse noise: A major problem,” Human Engineering 

Laboratories, Aberdeen Proving Ground, Maryland, US Army Technical Note 4-64, p.29; Nixon (1998), p.4. 

McKinley, Richard L. (2010). “Auditory and acoustic research and development at the Air Force Research 

Laboratory.” Acoustics Today, vol. 6, no. 1, p.22; and Chan et al. (2016), p.61. 

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Damage risk criteria (DRCs) for continuous noise rely upon epidemiologic analyses of populations 

of persons exposed over several years to noise in occupational environments.

47 The consensus 

exposure criterion for continuous noise is 85 dBA, 8 hours, with a 3 dB per doubling exchange 

rate, i.e. equal energy. The lack of human impulsive only exposure vs permanent hearing threshold 

shift data and the lack of detailed waveform vs temporary threshold shift for a variety of impulsive 

noises has led to the establishment of several DRC models. The following is a review of the 

development of the DoD damage risk criteria for impulsive noise.

i. Waveform parameter-based DRCs for impulsive noise exposure

In 1955 and 1957, Dr. Henning Von Gierke48, the fourth recipient of the NHCA Award for 

Outstanding Contributions to the Field of Hearing Conservation, published groundbreaking work 

in the area of noise exposure criteria.49 These early publications led to the first national criteria on 

"Hazardous Exposure to Intermittent and Steady State Noise," published by CHABA in 1965.50 In 

1968, "Proposed Damage-Risk Criteria for Impulse Noise (Gunfire)" was developed and published 

with extensive input from the Army.

Starting in 1995 until 1997, Army researcher Dan Johnson and the US Army Aearomedical 

Research Laboratory (USAARL) conducted a series of studies using human test subjects “to 

determine the safe limits of occupational exposure while wearing hearing protection”.51 These 

studies are known as the Blast Overpressure Studies (BOP). Johnson tested two nonlinear earplugs 

for this study: the Rucker Plug designed by USAARL and “a nonlinear plug designed at the 

French-German Research Institute of Saint-Louis (ISL), France”52. The ISL plug was also known 

as the “French no.1 plug” and was “a modification of the triple-flange E.A.R Ultrafit” plug that 

 47 See Murphy, William James, and Richard McKinley (2012). “A case for using A-weighted equivalent energy as a 

damage risk criterion for impulse noise exposure.” The Journal of the Acoustical Society of America, vol. 131, no. 4, 

p.1-29. See also ANSI/ASA S3.44 2016/Part 1/ISO 1999:2013 (MOD) (specifies method for calculating expected 

noise-induced permanent threshold shift at threshold levels for adult populations due to levels/durations of noise 

exposure, applicable to noise frequencies less than 10000 Hz - sound pressures exceeding 200 Pa (140 dB relative to 

20 μPa) is recognized as extrapolation).

48 Dr. Von Gierke was the Division Chief for Bionics and Bioengineering Division of the Aerospace Medical 

Research Laboratory when I was hired on in 1976.

49 Von Gierke, H. (1955). “Criteria for Short Time Exposures to High Intensity Jet Aircraft Noise”; And Von 

Gierke, H. (1957). “Criteria for Work Spaces, Living Spaces, and Other Airbase Areas.”

50 Nixon (1998). 51 3M_MDL000014015 at p.18. 52 Id. at p.72.

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“consisted of shortening the stem by 8mm and putting the filter designed at ISL, St Louis, France, 

in the front end of the plug”.53

In 1997, a revised military standard incorporating the CHABA proposed standard, while setting a 

limitation of 140 dB Peak SPL (unprotected), irrespective of the duration of the impulse (A vs B 

duration) was created commonly referred to as MIL-STD 1474 (1997) and utilized three categories 

for estimating and assessing risk: X-curve for single hearing protection (earplugs or muffs); Ycurve for dual protection (earplugs with muffs) and Z-curve for peak decibel levels of 180-190 and 

above. The 1474D standard assumed 29 dB of insertion loss for single earplugs assumed 35.5 dB 

(+6.5 dB shift from single earplug) for dual (earmuff plus earplug) protection.

ii. Equivalent energy DRCs for impulsive noise exposure

The equal/equivalent energy DRCs for impulsive noise exposure rely on the equal energy model 

of noise exposure that is used for assessing noise exposure/dose to continuous noise. The LAeq,8h

is the equal energy metric. LAeq,8h is used by NATO and the European Union54 to assess exposure 

to impulsive noise along with a 140 dB Peak level (unprotected) limit. LAeq,8h set to 85 dBA for 8 

hours is the normal criterion. Critics of the LAeq,8h metric state at it overestimates the hazard or 

damage risk from long duration impulses such as those from artillery or mortar firing as seen in 

BOP conducted at Albuquerque by Jim Patterson and Dan Johnson. The over estimation of hazard 

from long duration (1-2 ms) impulses by LAeq,8h is thought to be approximately10 dB. In order 

to make the LAeq,8h metric closer fit the human exposure data LAeq,100ms was proposed reducing 

the computed exposure relative to the “A”-duration of the impulse. LAeq,100ms uses the same equal 

energy model as LAeq8 but adjusted the exposure by up to 10 dB for impulses having long (1-2 

ms) A-durations. For short duration impulses, such as those from small arms fire, LAeq,100ms and 

LAeq8 give the same answer once corrected for the difference in time base. For long duration 

impulses, such as those used in the BOP studies, the LAeq,100ms better matches the human data 

resolving the over estimation of risk by LAeqA8.55

 53 Id. at p.50. 54 See McKinley, R, et al. (2012). “Using impulsive peak insertion loss of hearing protectors with impulsive damage 

risk criteria.” Presentation in The Journal of the Acoustical Society of America, vol. 131. 55 The acoustic energy criterion was initially developed by Atherly and Martin in 1971.

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One substantial advantage of the LAeq,8h type metrics is that the same metric can be used for both 

continuous noise and impulsive noise. Additionally, the exposure from each type of noise can be 

summed, and in the cases where impulsive noise is occurring simultaneously with continuous noise 

the LAeq metrics will deliver a reasonable assessment of the exposure. The LAeq metrics are

compatible with the use hearing protection and can easily use attenuation or insertion loss data in 

assessing noise exposure. Based on scientifically valid methodology, the LAeq8 /LIAeq100ms metrics 

have been instantiated as the impulsive noise exposure criterion in the USAF hearing conservation 

instruction standard for the U.S. Air Force and in MILSTD 1474E where it is available for use by 

US Navy/Marines. In context of BOP data, LAeq8 was evaluated regarding waveforms and 

exposure outcomes for 5 meter, 3 meter and 1 meter exposures and found to have the best 

Goodness-of-Fit and Discrimination of all models studied.56 LAeq8 unprotected exhibited the best 

Goodness-of-Fit.57

Figure 4

Figure 5

For context, recalling the prior discussion of military noise levels relating to small arms and other 

weapons, the below charts reflect of chart from NATO RTO TG, an international report on the 

evaluation and measurement of military noise levels which uses the A-weighted sound pressure 

level metric for continuous noise exposure. Again, within the European Union, the LAeq has been 

the metric of choice for impulsive noise exposure. 

 56 Murphy and McKinley (2012), “Case for using A-weighted.” 57 Id.

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Figure 6 NATO RTO, 3-14

i) Auditory model-based DRC

In 2006, the acquisitions part of the U.S. Army (led by researchers at Aberdeen Proving Ground –

ARL) proposed to update to MIL-STD 1474D with a new method called the Auditory Hazard 

Assessment Algorithm for Humans (AHAAH). This proposal would move away from the peak 

sound pressure level, envelope duration and number of impulses method of 1474D. A central 

component of AHAAH is the assumption that all humans have a middle ear reflex which provides 

additional biologically based attenuation from the contracting of the middle ear seen in cat 

models.58 This modeling thereby allows for more exposure for the “warned” soldier vs the soldier 

that is unaware and, hence, unwarned so as to expect an impulse. The AHAAH does not take into 

 58 See “AIBS Peer Review of AHAAH” (n.d.). Army Research Laboratory, https://www.arl.army.mil/who-weare/directorates/hred/ahaah/aibs-peer-review-of-ahaah/. 

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account change in the amount or prevalence of the contraction, assuming one exists for some or 

all people, and whether middle ear fatigue may occur during, for example, a training session with 

small arms on a range.59 The middle ear reflex is a point of continued controversy and has been 

called into question by Murphy, Flamme et al.60 One note, however, is that the AHAAH model 

may be utilized as a scientific tool by which certain impulsive noise analysis is beneficial. Certain 

underlying acoustical properties and the particular computations derived therefrom are sound. 

Specific to the CAEv2, both prior to, and after, correcting for non-linearity in 2015, and as 

explained further, the AHAAH modeling accurately predicted a troubling resonance at around 6.2k 

Hz which would affect attenuation and insertion loss with small arms fire and other weapons with 

an emphasis on higher frequency content. Unfortunately, as a general proposition, the National 

Institute for Occupational Safety and Health further undermined the overall validity of AHAAH 

as a Damage Risk Criteria through two separate evaluations of data used to justify the AHAAH 

methodology. NIOSH found that the use of the A-weighted equivalent energy LAeq8 was more 

suitable for the purposes of predicting the effects of temporary threshold shifts (TTS) both in 

humans and in chinchillas. The LAeq8 method provided best fit for the TTS outcomes and 

demonstrated the greatest discrimination (ability to predict TTS) when compared to AHAAH, 

MIL-STD 1474D and two other proposed DRCs. Similarly, LAeq8 was found to give the best-fit 

and greatest discrimination for the chinchilla impulse noise exposures. The LAeq8 affords the 

best sensitivity and specificity for discrimination of potential hazards and has the greatest level of 

integration with present occupational exposure standards and prospective hearing protection 

labeling regulations. Lastly, the American Institute of Biological Sciences (AIBS) in 2010 found 

AHAAH not to be a verified method and recommended the use of LAeq8.

b. Allowable Number of Rounds (ANOR) 

Allowable number of rounds is a calculated outcome applying the damage risk criterion to a 

specific environment and weapon type. While the three basic types of exposure criteria that have 

 59 See Patterson, James H., and William A. Ahroon (2004), “Evaluation of an auditory hazard model using data from 

human volunteer studies.” USAARL, report 2005-01. 60 See Murphy et al. (2009); “American institute of biological sciences peer review of injury prevention and 

reduction research task area impulse noise injury models” (2010); Fedele, Paul D., et al. (2013). “Using the auditory

hazard assessment algorithm for humans (AHAAH) with hearing protection software, release MIL-STD-1474E.” 

Army Research Laboratory, p.1-116; and Deiters, Kristy K., et al. (2019). “Generalizability of clinically measured 

acoustic reflexes to brief sounds.” The Journal of the Acoustical Society of America, vol. 146, no. 5, 3993-4006. 

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been presented (peak level and B duration; LAeq8; and AHAAH) all would give different answers 

regarding the allowable number of rounds. The critical issue is the amount of attenuation or 

insertion loss being provided by their hearing protector.61 The CAEv2 contained numerous design 

defects which exposed servicemembers to unnecessary risks due to a loss of attenuation for 

continuous noise and insertion loss for impulsive noise which would result in a reduction in the 

allowable number rounds or an increase in the hearing damage risk/exposure.

MIL-STD 1474D contains a table setting forth a numeric and arithmetic calculation as to the 

allowable number of rounds. Table 4-1, below. Impulse noise daily exposure limits:62

Figure 7

4. TESTING STANDARDS AND PROCEDURES TO ASSESS ATTENUATION FOR 

CONTINUOUS NOISE AND INSERTION LOSS FOR IMPULSIVE NOISE

a. Real Ear Attenuation at Threshold (REAT) Testing to determine attenuation for 

Continuous Noise Protection

 61 See DOD Touhy Production Document Touhy00000090, Kalb (1999), “ARL-HRED Hearing Protection Device 

Assessments in Reverberating Environments”; and Patterson and Ahroon (2004).

62 “Department of Defense design criteria standards: Noise limits” (1997). MIL-STD1474D, 

https://novaintegration.com/wp-content/uploads/2015/11/MIL-STD-1474D.pdf. 

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i. ANSI S3.19(1974) and S12.6(1997)

Early standards established for testing ear protectors were codified in ANSI S3.19 (1974). This 

standard was utilized by the EPA to derive a noise reduction rating for labeling the performance 

of a hearing protector for steady state or continuous noise.63 A key feature of this standard was 

the use of a trained experimenter who would perform the insertion of earplugs into test subjects, 

known as the experimenter-fit method. For years, debate ensued as to whether experimenter-fit 

over-estimated the protection provided to real world users. A variation of insertion called the 

subject-fit method gained traction after comparative studies reflected wide variances in attenuation 

when the subject was fit by a professional technician as opposed to the user. Subject-fit analysis 

was recognized as being more accurate in providing real-world attenuation data. To more 

accurately determine the effectiveness, a manufacturer would use a method by which naïve 

subjects as opposed to professional experimenter technicians would insert the plug themselves for 

a better estimated real-world attenuation.64 

In 1997, ANSI S3.19 was withdrawn and replaced by ANSI S12.6-1997.65 ANSI S12.6-1997 

provided for both an experimenter-fit and a subject-fit method called: Method A, found in Section 

8.2, and Method B, found in Section 9 of ANSI S12.6-1997. Whereas the prior ANSI S3.19 

provide for ten subjects to be tested, ANSI S12.6 provides for at least twenty subjects. Another 

change to procedure was as to the number of trials each subject undergoes. Whereas ANSI S3.19 

called for three trials, ANSI S12.6 called for two trials for each subject. Importantly, Section 9.2.3 

of ANSI S12.6-199766 states: “regardless of the fit of the hearing protector, or whether or not it 

changes position or breaks its acoustical seal, the data shall still be accepted.” only exception to 

this is if the HPD “falls out of the ear during the test,” in which case the experimenter terminates 

the test, enters the chamber and asks the subject to reinsert the HPD. If the HPD falls out a second 

time, the test is terminated and the subject is replaced. 

 63 The test procedures on which noise reduction rating (NRR) calculations as mandated by the US Environmental 

Protection Agency (EPA, 1979) are based on a 40-year-old ANSI standard (ANSI, 1974), now rescinded. 64 Berger, Elliott H., et al. (1996), “International review of field studies of hearing protector attenuation,” Scientific 

Basis of Noise-Induced Hearing Loss, ed. A. Axelsson, Hans Borchgrevink, Roger, Hamernik, Per-Anders 

Hellstrom, Donald Henderson, and Richard Salvi, Thieme Medical Pub., Inc., p.361-77. 65 See ANSI S12.6-1997. “Methods for Measuring the Real-Ear Attenuation of Hearing Protectors.” ANSI S3.19 

remained the required measure for testing protectors and deriving NRR labeling pursuant to ANSI S3.19.

66 Section 9.2.3 of ANSI S12.6-1997

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ii) ANSI S12.68

ANSI S12.68 entitled “Methods of Estimating Effective A-Weighted Sound Pressure Levels When 

Hearing Protectors are Worn,” and was developed in response to issues stemming from ANSI 

S3.19’s statistical treatment of REAT data, and to provide a method for calculating a modified 

NRR based off ANSI S12.6 REAT data.67 

To increase the precision of the prediction of protected A-weighted sound pressure level, simple 

white or pink noise was insufficient since that is, in effect, a C-weighted noise. Over the years, 

many different samples of noises from various sectors of industry and military have been collected. 

Yet, none had been formally applied for HPD specifications. A new HPD labeling rule needed 

such an increase in precision. The abstract of ANSI S12.68 states: 

This standard specifies three methods, in ascending order of complexity of 

use and potential accuracy, for the estimation of the sound pressure levels 

that are effective when a hearing protector is worn. The application of the 

procedures in turn requires an estimate of the real-ear attenuation of the 

device for groups of users and an estimate of the noise levels to which the 

users are exposed. The simplest method is the Noise Level Reduction 

Statistic for use with A-weighting (NRSA) that can be directly subtracted 

from an A-weighted sound level or sound exposure estimate. A more 

accurate procedure is the Noise Level Reduction Statistic, Graphical 

(NRSG) that requires measurements of both the A- and C-weighted sound 

levels or exposures, and the application of a set of graphical data. Potentially 

the most accurate approach is the octave-band method utilizing the octaveband real-ear attenuation and noise measurement data. Each of the 

simplified ratings, the NRSA and NRSG, is to be computed at both the 80th 

and 20th percentiles to reflect the range of performance to be expected 

based on the variation in the attenuation data.

b. Artificial Test Figure (ATF) Testing to determine insertion loss for Impulsive Noise 

Protection

i. ANSI S12.42

 67 ANSI-ASA S12.6-2008. 

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In the field of hearing conservation, assessing impulse noise presents certain challenges for the 

scientific community searching for noise exposure criterion.68 To accurately assess the hearing 

damage risk for both short and long duration impulses, ANSI 12.42 (2010) describes methods for 

measuring the peak insertion loss of hearing protection in impulsive noise.69 This standard 

describes an accepted method to apply the IPIL data to damage risk criteria for an estimate of 

allowable impulsive noise exposure when using hearing protection. Measures of IPIL performance 

of a protector are taken over a range of peak levels (130, 150, and 170 dB SPL). By way of 

example, a scientist might take a commonly used small arms weapon such as a Colt AR-15 0.223 

caliber rifle to create impulsive noise. Since the BOP Studies, no human studies have been 

performed in the United States. However, measurements may be taken using acoustic test figures 

which measure both free-field and ATF waveforms from the impulse noise source and apply signal 

processing to determine the noise exposure criterion. One such ATF is the French German Institute 

de Saint Louis (ISL) ATF. This ATF contains an ear IEC 711 Coupler along with a solid acrylic 

head form. Another next generation ATF is the GRAS 45 CB. This ATF includes heated ear canals

and longer ear canal built in accordance with ANSI S12.42-2010. The GRAS 45 CB ATF 

measures IPIL performance over a range of peak levels (130, 150, and 170 dB SPL), measured in 

both free-field and ATF waveforms to determine noise exposure criterion.70 Among the various 

methods, LAeq8 is the preferred method and has been roundly validated.

Figure 8

 68 McKinley, R., and H. Gallagher (2012). “Using impulsive peak insertion loss of hearing protectors with impulsive 

damage risk criteria.” Presentation in The Journal of the Acoustical Society of America, vol. 131. 69 ANSI/ASA S12.42: “Methods for the Measurement of Insertion Loss of Hearing Protection Devices in 

Continuous or Impulsive Noise Using Microphone-in-Real-Ear or Acoustic Test Fixture Procedures”. 70 McKinley and Gallagher(2012). See also ANSI S12.42-2010.

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Measurements of the unoccluded and occluded ATF are taken and computed using a free-field to 

ATF Transfer Function, described as:

Figure 9

Thereafter, calculations of unoccluded ATF using free-field pressure are taken, described as: 

Figure 10

Finally, computations are done for impulse reduction in a time domain, described as:

Figure 11

Data derived from the measures taken during testing for IPIL may be evaluated using various 

damage risk criteria described in this Report including MIL-STD1474D, LAeq and the AHAAH 

Model Unwarned/Warned. The use of an ATF to determine the insertion loss qualities of a hearing 

protector is designed to determine the functionality and effectiveness of the protector. Such studies 

are not designed to determine the wearability, function and effectiveness of hearing protectors in 

human subjects. In other words, human factors variables are not accounted for in ANSI 12.42 

testing for insertion loss, rather the use of real ear attenuation data gathered under ANSI 12.6 

(1997) and additional field studies with extended wear under real world conditions are better 

designed to determine if a particular protector will allow proper ready fit, seal and allow continued 

seal for a reasonable duration. 

ii. Limitations of ATF Testing

There are a number of limitations with ATF testing that prevents a hearing conservationist from 

determining the safety and efficacy of a protector. Those limitations are largely human factors 

elements. In an ATF test set up, the scientist inserts the ear protector in a manner that ensures full 

capture and closure between the protector and the ATF ear canal. This is not dissimilar to 

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experimenter fit under ANSI 3.19 REAT test in so much as the experimenter is taking as much of 

the potential for variations in insertion angle and depth and initial fit out of the equation. By way 

of example, a recent test on a triple flange Etymotic EB-1 B-1 BlastPLG by Murphy et al. 

commented on the lack of congruity between the size of the earplug and ATF artificial ear canal.71

Care was taken to ensure that a wrinkle or air leak was not created.72 In this regard, that 

phenomenon is not unlike what is caused by a loosening earplug. Minor separation between an 

earplug and the ear canal walls as created in a study by a probe tube caused dramatic difference in 

attenuation.73

5. HEARING PROTECTOR DEVICES (“HPD”) 

a. Brief Background on Early Development of Passive Linear Earplugs 

Noise induced hearing loss is nearly always preventable. Prevention involves limiting the noise 

exposure by either reducing the time of exposure and/or reducing the intensity of the noise at the 

ear. Noise intensity can be reduced at the source, in the path, and at the person. Source reduction 

and path reductions of noise are expensive and many times severely limit the performance of the 

vehicle or other system. Reductions of noise at the person have proven to be the most effective 

and least costly of the options.74

Many of the WWII pilots and aircrew stuffed cotton in their ears to try to reduce the noise. This 

was not effective. In 1944, the V-5lR was used to reduce the size of acoustic leaks.75 It was made 

of soft vinyl and originally came in three sizes. Later, in 1956, the plug came in five sizes, adding 

an extra small and extra-large size after a study examining eight sizes by Blackstock and von 

Gierke.76

 71 Murphy, WL et al. (2015). “Comparison of performance of three acoustic test fixtures using impulse peak 

insertion loss measurements.” The Journal of the Acoustical Society of America, vol. 130, no. 4, p.1-45. 72 Id. at 14. 73 See 3M_MDL000335736 and 3M_MDL000322632. 74 McKinley, R. and Bjorn, V. (2004). “Passive Hearing Protection Systems and Their Performance” (presented at 

the RTO HFM Lecture Series on "Personal Hearing Protection including Active Noise Reduction", held in Warsaw, 

Poland, 25-26 October 2004; Belgium, Brussels, 28-29 October 2004; Virginia Beach, VA, USA, 9-10 November 

2004, and published in RTO-EN-HFM-111 at p.2-1. 75 Id. at p. 4. 76 Id.

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Figure 12

Other configurations included a triple flange earplug with three different diameter flanges mounted 

on a stem. They came in small, medium and large. However, later designs that included a foam 

hand-formed product provided a one size fits all, which provided a more simple and effective 

means to dispense earplugs to protect soldiers.

77

Figure 13

i. Level-Independent Linear (LIL) HPDs

The multi-sized V51-R single-flange earplug was a form of HPD known as a “level-independent 

linear” (LIL) attenuation plug. Other passive linear earplugs that have been used in the military 

include both the disposable EAR one-size-fits-all yellow cylindrical foam plug and the pre-molded 

reusable one-size-fits-most triple flange EAR Ultrafit. The V-51R foam earplug and Ultrafit all 

provide a consistent and uniform attenuation across frequencies such that, assuming proper fit and 

 77 Id.

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seal, they each provide the level of attenuation at 90 dB SPL at 140 dB SP. Linear HPDs are 

intended for maximum protection against all offending noise types (continuous, intermittent, and 

impulse) and sound levels. As such, these protectors necessarily compromise auditory situational 

awareness.78 That is, speech and other low-level sounds of importance in the environment may 

go undetected or poorly heard. Linear HPDs therefore have played an important role over the 

years in maximally protecting servicemembers from hazardous noise, especially in non-conflict 

training and operational activities, but they have some disadvantages for use when audible 

instruction or communication is necessary or when situational awareness is beneficial for mission 

success.

ii. Situational Awareness

Among the five human senses, hearing is critical for military mission success and situational 

awareness for survival on the battlefield. It is active at all times, 24/7, 365 days a year across the 

listener’s full continuum of perception, including detection, recognition, discrimination, 

identification, and localization of sound sources from locations in front, to the side, behind, below, 

or above the service member. While in the military, he or she may be expected to encounter the 

widest possible range of sound levels and spectra from the softest footsteps of an adversary to 

small arms fire to “booming” munition fire from howitzers, mortars, and other heavy artillery. No 

other sense, including vision, affords this breadth of coverage of the service member’s sensory 

environment. Most importantly, the sense of hearing serves as the primary modality for 

communicating and responding to voice commands under life-threatening combat conditions. 

These communications often are made under the most challenging signal-to-noise conditions, 

during times of great demand of cognitive resources while under enormous stress. Indeed, noisy 

combat situations may reduce or limit the audibility of voice communications, contributing to 

miscommunications that may have dire consequences for personal and unit morbidity and 

mortality and, in turn, mission success.

iii. Level-Dependent Nonlinear (LDNL) HPDs 

 78 Brungart, D., et al. (2003). “Auditory localization in horizontal plane with single and double hearing protection 

evaluation.” Aviation, Space, and Environmental Medicine, vol. 74, no. 9, p.937-46. 

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b. Chronological Evolution from Early Development of Nonlinear Filters to the 

Design and Sale of the Combat Arms Version 2 (CAEv2) to the U.S. Department 

of Defense 

i. Nonlinear Filters and Earplugs to Address Need for Situation 

Awareness

The primary objectives of level-dependent nonlinear (LDNL) hearing protection devices (HPD’s) 

were to improve situational awareness and voice communication while also providing adequate 

protection against occasional high-level blasts and impulse noise of the kind encountered in 

military training and combat situations. These new LDNL HPDs were engineered to offer little or 

no attenuation for low-frequency noise and relatively small amounts of attenuation for mid and 

high-frequency noise at levels below those considered to be dangerous for impulse and blast 

exposures (i.e., < 140 dBp SPL). For higher impulse noise levels, the protection provided by the 

LDNL HPD was designed to increase the mid and high-frequency attenuation progressively as the 

offending noise level was increased, while less affecting attenuation for frequencies of the noise 

at and below ~500-1000 Hz. At the highest levels of protection, the full peak attenuation for the 

LDNL HPD would closely approximate that afforded by a comparable linear HPD.79 Thus, the 

ideal properties of an LDNL HPD were: (1) transparent transmission of voice and speech 

information and other soft low-frequency signals important for situational awareness at all noise 

levels; and (2) protection against dangerous levels of impulse and blast noise that increase with 

the level of the offending noise. This was exemplified by the amplitude sensitive Gunfender.80

ii. The First NonLinear Earplug – “The Gunfender”

In or around 1969, a single-flanged nonlinear device called the Gunfender, marketed by Racal 

Safety Ltd, came to market.81 The Gunfender implemented a single-orifice metal plate to achieve 

its increasing acoustic resistance as the peak impulse level was increased.82 This protector 

 79 Amrein and Letowski (2012). 80 Mosko, J.D., and Fletcher, J.L. (1971). “Evaluation of the Gunfender earplug: temporary threshold shift and 

speech intelligibility.” Journal of the Acoustical Society of America, vol. 49, p.1732-33. Shaw, 1981 81 Forrest, M., and R. R. Coles (1970). “Problems of communication and ear protection in the royal marines.” 

Journal of the Royal Naval Medical Service, vol. 56, no. 1, p.162-69. 82 Mosko and Fletcher (1971). 

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essentially modified the V-51R plug with a 0.025-inch (0.0635 cm) diameter opening into the ear 

canal.83 A single-flanged earplug for which the center of the earplug had been removed and 

replaced with a metal plate-filter with a singular sharp-edged orifice,84 but which begins to linearly 

attenuate at around or above 110 dB and shows greater levels of protective attenuation over 

140dB.85 Importantly, the diameter of the orifice in the Gunfender metal filter-plate was 0.012” 

which, as Elliott Berger stated in an email to Kevin Ho on June 6th 2012, is the same as the orifice 

used in the filter in the Combat Arms Earplug.86

Figures 14(a) (left) and Figure 14(b) (right)

Level-Dependent, or Amplitude-sensitive, Hearing Protection Devices (HPDs) provide minimal 

attenuation at low sound levels but increased protection at high levels of steady-state and impulsive 

noise. A dynamically-functional valve or sharp-edged, round or slit-shaped orifice that opens into 

a duct in the protector constitutes the nonlinear element that changes attenuation. The valve-type 

devices incorporate a flutter valve which closes off the duct when activated by high sound 

pressures. The orifice-duct technique takes advantage of the physical behavior of acoustic 

resistance as the ratio of acoustic pressure on a material and particle velocity through it. Lowintensity sound waves predominantly exhibit laminar airflow and pass relatively unimpeded 

through the aperture, whereas high-intensity waves involve more turbulent flow and are attenuated 

due to the sharply increased acoustic resistance of the aperture. This technique has been applied 

 83 Id. 84 Mosko and Fletcher (1971). 85 Forrest, M.R. (1971), “Ear protection and hearing in high-intensity impulsive noise.” Occupational Hearing Loss, 

ed. D.W. Robinson, Academic Press for the British Acoustical Society. See also Forshaw, S.E., and J.I. Cruchley 

(1982). “Hearing protector problems in military operations.” Personal Hearing Protection in Industry, ed. P.W. 

Alberti, Raven Press. 

86 3M_MDL000314462

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with success in earplugs, such as the "Gunfender" which has been used by British military for 

twenty years.87

iii. The Hocks Filter (as configured with a host of earplug designs)

In 1974, another design was born called the Hocks Noise Breaker, marketed as part of the Aural 

Technology Protectear earplug. HPDs used today by U.S. military personnel and militaries around 

the world still utilize the Hocks filter or filters with slight variations that maintain the same 

fundamental design.88 The filter converts sonic energy into thermal energy by means of 

compression acceleration.89 These include the triple flanged Surefire Sonic Defender (EP4) which 

is approved for use by the U.S. military and utilized throughout the world for linear and nonlinear 

protection. The Hocks also remains the filter of choice for military and civilians seeking a custom 

molded earplug with nonlinearity. Custom earplugs often minimize acoustic leaks due to improved 

fit.90 

iv. The Combat Arms Version 1/ ISL French Filter

After 20 years of experience with nonlinearity in plugs with the Gunfender and Hocks filter plugs, 

ISL sought to improve nonlinearity in a new plug design based on the Gunfender filter. ISL 

realized this by creating three prototype filters: (1) filter No.1, consisting of two plates, each with 

an orifice with diameter d = 0.6mm and thickness e=0.3, separated by a crosspiece of length 

L=8mm and inside diameter D=2mm; (2) filter No.2. with an orifice with diameter d=0.3mm and 

thickness e=0.1mm, separated by a crosspiece with length L=6mm and inside diameter D=3mm; 

and (3) Filter No.3 which was a hybrid of the two. The final configuration would derive from filter 

No. 2 but with a length of 3.72mm. 

a. Development of the ISL Filter 

 87 3M_MDL000321663 88 Abel, Sharon M., and Ann Nakashima (2008). “An investigation of the attenuation provided by the Surefire EP3 

Sonic Defender earplug.” Defence Research and Development Canada, Technical Report TR2008-040. See also 

Murphy, William James (2015), “Protecting hearing from impulsive noise,” NHCA Spectrum, vol. 32, p.1-6. 

89 Hocks, K. (2010). “Focus On: Hearing Protection.” https://www.hearingreview.com/hearing-products/focus-onhearing-protection. 90 McKinley and Bjorn (2005). 

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The first step undertaken by the ISL in arriving at filter No.2, came from ISL testing of multiple 

single-plate single-orifice that varied the diameter and thickness of the orifice within each 

individual plate. Each of these plates were tested in a Gunfender. Of the seven variations of metal 

plate filters tested, the optimum plate configuration was found to have a thickness of 0.1mm and 

an orifice diameter of 0.3mm, exactly half of that of the original Racal Gunfender acoustical filterplate, which has a thickness of 0.2mm and an orifice diameter of 0.6mm.91

 92

 Figure 15: e = Thickness d=Diameter

 91 3M_MDL000325290

92 3M_MDL000009240

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Figure 16 3M_MDL000325290

After realizing the optimum single-plate filter configuration, ISL tested them for nonlinear 

attenuation characteristics using a Plexiglas fixture that would allow multiple filter plates to be 

held in-series.93 Two filter-plates in-series were better than all measurements conducted using a 

single plate. The length (L) and inside diameter (D) of the crosspiece for a two-plate configuration 

was then studied by the ISL using two plates with the aforementioned d=0.3mm and e=0.1mm 

sizing. Testing was conducted on prototypes with L=1mm, 2mm, 4mm, 6mm, and 8mm from 

which the ISL ‘arbitrarily decided to use the value L=6mm for the crosspiece length in order to 

observe the impact of the inside diameter (D) of the crosspiece (D= 2mm, 3mm, and 4mm)’. In 

their 1997 report ISL states that they could not use the value D=4mm as that gave the filter an 

outside dimeter of 5mm wish would make the ‘total bulk too large to be inserted into an earplug 

and into the auditory canal’ (emphasis added).94 A third plate was considered but, “the presence 

of a third plate does not result in a useful improvement.’95

 93 3M_MDL000325290

94 3M_MDL000012231

95 3M_MDL000325290

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b. Choosing a Plug for the New Nonlinear Filter 

In September 1989 and then again in September 1990, ILS conducted testing into the protective 

nonlinear characteristic of earplugs at Etablissement Technique de Bourges (ETBS).96 The 1989 

experiment tested 3M‘s EAR Foam and ER-20 prototype earplugs, against the Gunfender and the 

Jrenum LD3.97 Both the Gunfender and the ER-20 prototype plug were used with subjects exposed 

to 10 to 20 Howitzer rounds on the Firing range at ETBS. 11 subjects were exposed for 10 rounds 

at 30 second intervals using the Gunfender; however, due to the small number of ER-20 prototypes, 

only a small number of subjects (6) six were exposed wearing them, 4 subjects for 20 rounds and 

2 subjects for 10 rounds. No subjects were found to have a significant threshold shift (<10dB) from 

using either the ER-20 prototypes or the Gunfender.

98 .

In July 1990, 3M entered into a licensing agreement with Etymotic Research in to acquire the 

Intellectual Property rights to sell the ER-20 Hi-Fi plug.99 The finalized ER-20, an “almost 

identical” product, would be used in a second round of testing, along with the Racal Gunfender, 

conducted in September 1990 at the ETBS, to investigate the efficiency of “perforated” earplugs 

through human subject testing on small arms, Howitzers, and Anti-Tank devices.100 This study 

included a Modified Ultrafit A with a 1 to 1.5 mm channel bored from the tip of the flanges to the 

base of the stem and a Modified Ultrafit B that had the same channel but a plastic tube with a 

diameter of 1.57mm was equipped to its proximal (tympanic) end.

101 The study researchers at ISL 

concluded that ‘a nonlinear (perforated) earplug represents the best answer to the problem of the 

hearing protection against the impulse noise produced by weapons without restricting the 

operational ability of the soldiers. Such a device, if easy to fit by an inexperienced individual, 

could be sufficient to protect the ear during the infrequent shooting exercises of the military 

training’ (emphasis added).102

 96 Technical Establishment of Bourges 97 3M_MDL000319051

98 Id. 99 For the licensing agreement, see 3M_MDL000423921. 100 3M_MDL000319051 101 See Berger 30(b)6 Tr. 48:6-9. 102 3M_MDL000319051 

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c. Early Warnings Signs

i. French ISL Filter Leak Problems

Between 1995 and 1997, Dan Johnson conducted BOP studies on human subjects. The purpose 

was “to determine the safe limits of occupational exposure while wearing hearing protection.”103

Johnson tested two nonlinear earplugs for this study: the Rucker Plug designed by USAARL; and 

“a nonlinear plug designed at the French-German Research Institute of Saint-Louis [ISL], France” 

combining a modified UltraFit earplug with a metal No.2 filter that had the same dimensions as 

the previously discussed filter but, ’due to some technical reasons’ used a Length of 1mm104. The 

ISL plug “consisted of shortening the stem by 8mm and putting the filter designed at ISL, St Louis, 

France, in the front end of the plug.”105

During the BOP testing of the ISL plug, it was found to have leaking issues. Thus, ISL experiments 

done in the USA on American soldiers equipped with earplugs with filter No. 2, leak problems 

arose as a result of poor positioning of the earplugs (perforated EAR decided to ‘determine the 

impact of these leaks (corresponding in reality to a lack of peripheral seal)’. et al. decided to 

‘determine the impact of these leaks (corresponding in reality to a lack of peripheral seal)’ (Id.). 

ISL found that, by boring holes with a diameter of 0.3 mm and 0.6 mm into the earplug-likesupport that housed the filter, nonlinear attenuation was degraded by ‘several decibels’ for a leak 

of 0.3 mm and that when the size of the leak was doubled to 0.6 mm in diameter the degradation 

was ‘very clear’.106 The leak experiments conducted by ISL were done using a Plexiglas earpluglike-support as opposed to an ergonomically designed earplug, however ISL concluded that these 

earplug-like-supports do ‘not completely reflect the reality’ and that ‘an earplug like the EAR 

UltraFit, poorly positioned in the auditory canal, may have leaks with lengths much smaller 

than the entire earplug, and may thus considerably reduce the filter’s attenuation.’107 (emphasis 

added). 3M/Aearo was well-aware of these words of caution, which related to a tip configuration 

 103 3M_MDL000014015, p.18 104 Id., p.72. 105 Id., p.50. 106 3M_MDL000325290 107 3M_MDL000325290 at p.2: ”The size of the acoustic leak between the hearing protector and the head has a 

dramatic effect on passive hearing protector performance.” Viallet, Guilhem, et al. (2015). ”Investigation of the 

variability in earplugs sound attenuation measurements using a finite element model,” Applied Acoustics, vol. 89, 

p.336: ”In practice, a leakage can be due to a non-optimal fitting of the EP in the EC by the user.” 

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that was not yet made and was complicated by adding an opposing flange and enlarging the adapter 

stem well past the recommended 4.2 mm.

ii. Impact of Position of the Filters Inserted into Ultrafit

Another issue raised during BOP was the filter positioning within the modified Ultrafit plug. ISL 

found that, when testing filter placement, if the filter was placed at the tip of the Modified Ultrafit 

plug there was a ‘disappearance of the nonlinear effect for frequencies over 5000 Hz’. Upon 

analyzing the NR attenuation levels LAeqs and Nrpeak as a function of the external excitation 

levels for both Filter No.1 and Filter No.2 at varying positions within the Ultrafit earplug, the 

researchers at ISL found it was ‘preferable to place the filter in the inner half of the earplug, if not 

at its inner end, to obtain the best results.’ From this, 3M/Aearo focused on the importance of the 

resonance effect, a conclusion that the filter pushed farther towards the back of the plug would 

optimize the dampening of any standing resonance beyond the resonance expected relating to the 

in-ear volume of air between the plug and TM. 

 

Figure 17 from Hamery et al. 1997

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c. Dual Ended Plug - One Among Several Options

In November 1997, Garinther of the United States Army visited ISL to observe the work it was 

doing in creating passive nonlinear plugs. Importantly, three alternative design options were 

available: 

(1) “A nonlinear earplug and a separate normal earplug” (noted herein below: the choice 

chosen by the French military who rejected the CAEv2)108; 

(2) “a nonlinear earplug in which the acoustical channel can be closed” (Noted, below, 

this was already discussed as a documented concept with a dimensional drawing several 

months earlier on July 4, 1997 and would one day become the single ended type version 

found with the CAEv3 and CAEv4)109; or 

(3) “a reversible earplug that has a nonlinear earplug at one end and a normal earplug at 

the other” (the CAEv2).110

1. Option #1: A nonlinear earplug and a separate normal earplug

Despite patenting the dual sided design in 1997, ISL voiced a preference for the single-ended 

design based on feedback from the French military which, according to Hamery and Dancer ISL, 

found it difficult to ‘verify if the plug is well fitted.’111 Their preference manifested in what they 

called the ’simple nonlinear earplug’ (image below) that they sold to the French, Belgium and 

German Militaries.112

Figure 18: P0104A; 3M_ MDL000259866

 108 See Berger 30(b)6 Tr. 103:8-13. 

109 See Berger 30(b)6 Tr. 107:14-108:1. 110 DOD Touhy Production Document Touhy0000059. See also Berger 30(b)6 Tr. 108:15-19. 111 3M_MDL000003061 at p.70 112 3M_MDL000003061 at p.69

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The Simple Nonlinear Earplug, also known as the European Nonlinear Earplug (ENLE) is, in its 

very essence, a simple and safer alternate design to the CAEv2. The plug comprises of only two 

parts, a hollow-stem Premolded classic Ultrafit tip and the ISL Nonlinear Filter. This design avoids 

using a hard-plastic113 barbed stem-housing to hold the filter into the plug meaning that:

• the diameter of the plug under the third flange is, at most, 6.15mm or 0.245”114

(Compare to that of the CAEv2 at the same point which is, at most, 7.6mm or 

0.302”115) 

• The plug is more flexible compared to the CAEv2, meaning that it is more adapted 

to deal with normal mandibular movements, allowing for less walk-out. 

2. Option #2: a nonlinear earplug in which the acoustical channel 

can be closed 

In April 1997 Marc Doty, an employee at 3M/Aearo, drafted a prototype drawing of a nonlinear 

Ultrafit plug that functioned by twisting the base of a modified Ultrafit plug to either block or 

allow sound to travel through an acoustic channel.116 This plug is described and shown in the ISL’s 

R128/97 report published November 18, 1997.117 On July 4th 1997 ISL received insertion loss data 

for, and the first prototype of, the ‘stem version of the nonlinear plug’ from 3M/Aearo .118

3M/Aearo was advised that the stem must be thinner. ISL warned: ‘(ISL) is not sure that the 

present configuration will be suitable for most ears because of fitting problems’ because the 

outside diameter of the stem at the filter is 4.2 mm’ (emphasis added). 

 113 Delrin 114 X + (Y - Z) where X is the diameter of the filter (3 mm or 0.118”), Y is the diameter of the Ultrafit plug (5 mm or 

0.200“), and Z is the diameter of the hole born through the Ultrafit plug ( 1.85 mm or 0.073“). 115 X + (Y - Z) where X is the diameter of the barbed filter housing at its widest point (4.45 mm or 0.175”), Y is the 

diameter of the Ultrafit plug (5 mm or 0.200“), and Z is the diameter of the hole born through the Ultrafit plug ( 1.85 

mm or 0.073“).

116 See 3M_MDL000572003. 117 See diagram 1 in 3M_MDL000325290. 118 3M_MDL000427468

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Figure: 19

In January 1998, 3M/Aearo began redesigning the drawings made by Marc Doty in April of the 

previous year,119 and then in April 1998, filed for a patent for a single-ended passive nonlinear 

earplug that could be opened and closed by turning or twisting a knob at the base of the earplug 

stem in order to open and close an acoustic channel.120

3M/Aearo and ISL entered into a licensing agreement on March 3, 1999.121 It is from this date 

forward that 3M/Aearo held the intellectual property and manufacturing rights to a single122 and 

dual-ended123 earplug and the ISL nonlinear filter124. Thus, when the defects of the plug were 

uncovered during the initial 213015 testing on the CAEv2, 3M/Aearo had the option to return to a 

single-sided nonlinear earplug design that they had created back in 1998 or to begin creating a 

different single-sided device in line with the other two options presented in November of 1997.

 119 3M_MDL000572003 and 3M_MDL000571997 120 3M_MDL000338061 121 3M_MDL000020535 122 3M_MDL000338061 123 3M_MDL000692972 and 3M_MDL000188664 124 3M_MDL000188671

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3. Option #3: a reversible earplug that has a nonlinear earplug at 

one end and a normal earplug at the other: 

The third option, the dual-ended plug, was ultimately the one that 3M/Aearo decided to use in their 

CAE v2 device. The CAEv2 used 3M/Aearo’s own closed-core Ultraflex in the linear end of the 

device as seen in Figures 21 and 22. The ISL acoustic filter was embedded within the end of the 

adapter in the barbed plastic stem, as seen in Figure 21. 

In the initial prototype for the CAE v2, the sound-entry port was located slightly off center towards 

the nonlinear end of the plug, shown in Figure 21. This design mimicked the ISL dual-ended plug 

for which the stem of the closed linear end was slightly longer than that of the nonlinear end 

Compare Figure 21 with Figure 22. Aearo, on their own their accord, cut off part of the green 

Ultraflex stem on the linear end of the device. 

By shortening the stem on the linear end of the device, the sound port was moved into the middle 

of the adapter stem which then pushed the adapter deeper into the linear end of the device, shown 

in Figure 22. The widest part of the filter, measuring 4.45 mm wide as shown in Figure 20, was 

now well into and under the third flange. 

DESIGN DRAWING OF THE FILTER WITH ADAPTER125

Figure: 20

 125 Falco Exhibit 3; 3M_MDL000017774. 

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DESIGN DRAWING OF LONGER VERSION WITH ULTRAFLEX STEM INTACT126

Figure: 21

DESIGN DRAWING WITH ULTRAFLEX STEM CUTDOWN (FINAL CAEV2 

CONFIGURATION)127

 126 Falco Exhibit 3; 3M_MDL000017774 127 Falco Exhibit 3; 3M_MDL000017774

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Figure: 22

MAGNIFIED PICTURES OF LINEAR GREEN END AND NONLINEAR YELLOW END

Figures: 23 and 24

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In November of 1997, Aearo/3M has already undertaken efforts to design a Combat Arms hearing 

protector to provide nonlinearity. The choices presented include a single ended nonlinear standalone product, a single ended product with both nonlinearity and linearity, or possibly a dual-ended 

plug with both capabilities. In that moment, Aearo/3M were obligated to undertake design efforts 

consistent with all international standards (ISO 9001); national standards (EPA guidelines) and 

general good manufacturing practices.

6. HEARING PROTECTOR DESIGN - ENGINEERING CONSIDERATIONS 

a. ISO 9001 Standards

The International Organization for Standardization provides the international standard for quality 

systems. In order to become registered with the ISO, a party has to have a prescribed list of policies 

and procedures in place.128 After establishing and putting in place a program with sufficient 

standards robust enough to meet the necessary requirements, an independent auditor conducts a 

review of these processes and procedures and then determines whether or not a party can be 

registered as an ISO-registered firm.129 ISO registration is valued by the global community due to 

its nature as an international standard for having quality systems in place. In short, ISOregistration has become the industry standard. This is in large part because of customer demand 

after widespread recognition as a known registrar.130 ISO registration can help to provide a level 

of confidence in the manufacturer.131

At the time the Combat Arms Earplugs were in development and entering production, a primary 

applicable standard would have been ISO 9001: 1994 Quality Systems - Model for quality 

assurance in design, development, production, installation and servicing methodology and 

standard. Aearo’s Indianapolis, Indiana Stock Safety Division was certified to ISO 9001: 1994 

during the design and development of the Combat Arms Earplug version 2.132 The purpose of such 

a standard is to establish reliability and other controls in the manufacturing process of new 

products, such as the Combat Arms Earplug. Specifically, ISO 9001: 1994 sets forth:

 128 See Todor Tr. 17:15-19:15. Mr. Todor worked as a quality assurance engineer at Aero from April of 1993 to 

2009. Prior to that, he worked at a company called CMW, Inc. as Director of quality assurance. There, he worked 

with some ISO 9002 quality systems

129 See Todor Tr. 17:15-19:15. 130 See Todor Tr.17:15-19:15. 131 See Todor Tr. 19:6-10. 132 3M_MDL000423679 at p.2.

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The International Standard is applicable in situations when (a) design is required and the product 

requirements are stated principally in performance terms, or they need to be established, and (b) 

confidence in product conformance can be attained by adequate demonstration of a supplier’s 

capabilities in design, development, production, installation and servicing.133

In assessing design and manufacturing processes, ISO 9001: 1994 evaluates a myriad of process 

areas and the potential impact of specific quality system requirements and the extent to which this 

impacts the overall sufficiency and adequacy of these processes. Specifically, ISO 9001 “specifies 

quality system requirements for use where a supplier’s capability to design and supply conforming 

products needs to be demonstrated.”134

Section 4.2.1 of ISO 9001: 1994 identifies general requirements for a quality system and requires 

development of a manual. In this respect, general requirements and the accompanying manual 

should lead to a quality system that ensures conformity of the product to specified requirements. 

A quality manual should include elements such as a general quality policy, quality objectives, 

quality procedures, audit procedures, as well as introduce organizational structure, work practices, 

and other implementation procedures.135

Other sections of ISO 9001: 1994 go into great detail in terms of the quality system requirements 

to be assessed for a manufacturer in determining the adequacy of the design and development 

process. These requirements include:136

a. Management responsibility (§ 4.1.1.)

b. Resources (§ 4.1.2.1)

c. Quality system (§ 4.2)

d. Contract review (§ 4.2)

e. Design control (§ 4.3)

f. Design input (§ 4.4)

g. Design output (§ 4

h. Design review (§ 4.4.6)

 133 ISO 9001:1994 § 1. 134 ISO 9001:1994 § 1. 135 ISO 9001:1994 (§ 4.2.1). 136 ISO 9001:1994 (passim).

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i. Design verification (§ 4.4.7)

j. Design validation (§ 4.4.8)

k. Design changes (§ 4.4.9)

l. Document and data control (§ 4.5)

m. Purchasing (§ 4.6)

n. Control if customer-supplied product (§ 4.7)

o. Product identification and traceability (§ 4.8)

p. Process control (§ 4.9)

q. Inspection and testing (§ 4.10)

r. Control of inspection, measuring, and test equipment (§ 4.11)

s. Inspection and test status (§ 4.12)

t. Control of nonconforming product (§ 4.13)

u. Corrective and preventive action (§ 4.14)

v. Handling, storage, packaging, preservation, and delivery (§ 4.15)

w. Control of quality records (§ 4.16)

x. Internal quality audits (§ 4.17)

y. Training (§ 4.18)

z. Servicing (§ 4.19)

aa. Statistical techniques (§ 4.20)

This multifaceted evaluation of such a broad range of aspects of the design and development 

processes highlights the potential for critical impacts from defects in quality systems for new 

products. This thorough assessment of the design and development processes is necessary for each 

manufacturer to ensure compliance with specifications set forth for the product and the demands 

and tolerances of the product. Because of Aearo’s ISO registration, these standards were certainly 

applicable to the design and development of the Combat Arms Earplug.137 As such, the Defendants 

should have complied with the stringent standards set forth for quality systems for the design and 

development of a new product, such as the Combat Arms plug. The CAEv2 was designed and 

developed in violation of the standards set forth in ISO 9001: 1994. 

A crucial aspect of the ISO 9001 :1994 standard is evaluating and ensuring that quality system 

elements are reliably and consistently applied to the design and development process for a new 

product. The goal of this exercise is to provide consistent and reliable results of design input and 

output procedures, such that there can be verification and validation of the design process and 

 137 3M_MDL00042367 at 2.

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consistency in production of the product.138 In this respect, ISO 9001 provides a reliable and 

consistent methodology for evaluation of the reliability and depth of the design and development 

process, beginning with its inception and development, continuing through to execution, along 

with necessary follow-up, documentation, and review. Because of the objective criteria set forth 

by ISO 9001, a general, reliable standard can be referenced for the design and development of new 

products. As a result of access to a ubiquitous standard and the accompanying reliability and 

consistency that is expected from adherence to this standard, customers place additional 

confidence in both the manufacturer and its design and development processes.139

For example, ISO 9001: 1994 Section 4.4 sets forth the requirements for product development and 

design.140 Reliability, consistency, and thorough documentation are the cornerstones of meeting 

the standard for controlling the design and development process for a new product. In terms of 

design input, procedures should be in place to account for a variety of requirements for the product, 

including customer expectations, contractual conditions, safety considerations, performance 

standards, functional specifications, and other characteristics expected for the necessary 

performance of the new product.141 Design verification is also an important aspect that must be 

assessed in evaluation the design and development process. Design validation procedures should 

be in place to validate that the newly designed product meets the performance and functionality of 

the product expected by the customer.142 Design validation includes ensuring that a newly designed 

product is manufactured in a process that confirms that the product will perform properly under 

real world conditions, meet the agreed-to expectations of the customer, and that this validation 

process occurs early in the design process.143 The requirements of ISO 9001 :1994 all go hand-inhand and involve a holistic, objective assessment and reliable methodology for evaluating quality 

systems and the design and development process. Accordingly, design inputs, for example, are 

critical to the design validation process, which in turn is crucial to the quality, safety, and 

functionality of the final product. 

 138 ISO 9001:1994 (§ 4.4).

139 See Todor Tr. 19:6-10. 140 ISO 9001:1994 (§ 4.4). 141 ISO 9001:1994 (§ 4.4.4). 142 ISO 9001:1994 (§ 4.4.8). 143 ISO 9001:1994 (§ 4.4.8).

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From a review of the testimony, documents, and other information provided regarding the conduct 

and implementation of the design and development process by the Defendants, it is clear that the 

Defendants deviated significantly from the applicable standard and appropriate practices 

established by ISO 9001: 1994 and failed to generally follow the requirements set forth by ISO 

9001: 1994. Additionally, it is equally clear from a review of the records and testimony related to 

the design and development of the Combat Arms Earplug that the failure to comport with the 

requirements and standards set forth in 9001 :1994 led directly to production of a product that was 

intrinsically unable to satisfy the safety requirements, functionality, customer expectations, and 

other requisite specifications for the product. The requirements of ISO 9001:1994 provide a 

reliable and objective methodology for assessing the inadequacy and failures of the Defendants in 

this regard. In addition, the application of general engineering principles, standards, and practices 

also lead to the same conclusion that inadequate or improper design and development practices 

were implemented in the production of the Combat Arms Version 2 earplug. 

Notably, the CAEv2 did not comply with the customer’s expectations—in this case, the US 

Military. The US Military’s Military Procurement Item Description (MPID 1 & 2) calls for 100% 

sampling inspection of the yellow end of the earplug.144 Moreover, despite the requirements of 

ISO 9001, the Defendants failed to include a plan to compare the design of the CAEv2 with other 

proven, similar designs, and also failed to conduct any test planning or testing of the CAEv2 prior 

to sale, which departed from the ISO 9001 requirements identified above. Additionally, the 

Defendants failed to test both ends of the CAEv2, as was required by the standards. 

Certainly, it was the case that a “customer like the United States military would need and expect 

that the products will have . . . met the quality testing standards that were promised to them when 

they agreed to buy the product.145 The CAEv2 did not.

 144 3M_MDL000257850 and 3M_MDL000002017 145 See Todor Tr. 169: 11-19.

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b. Noise Control Act of 1972

In addition to well-understood and established standards in design engineering (ISO 9001), 

specific to the hearing protector industry, an important piece of legislation was the Noise Control 

Act of 1972. Congress enacted this Act to “promote an environment for all Americans free from 

noise that jeopardizes their health or welfare.” One purpose of the Act was “to provide information 

to the public respecting the noise emission and noise reduction characteristics of products 

(distributed in commerce).” In 1979, the EPA published Regulatory Analysis Supporting the Noise 

Labeling Requirements for Hearing Protectors. Publication included comments and testimony 

taken during a public meeting attended by numerous earplug manufacturers. Elliot Berger 

represented Aearo. This moment marked a key regulatory springboard for the EPA’s establishment 

of stringent labeling requirements for all hearing protectors. The EPA Regulatory Analysis 

delineated a number of key design factors, including: 

1. Use Requirements/Environment;

2. Fitability; 

3. Comfort; and 

4. Biological Compatibility. 

Notably, Berger would later identify similar factors in his Noise Manual, 4th Edition in 1986.146

Paraphrased in pertinent part, Berger’s list is prioritized emphasizing these same factors:

1. Comfort. ignored in laboratory tests but crucial in the real world.

2. Utilization. Due to poor comfort, earplugs may be incorrectly inserted or adjusted.

3. Fit. Fitting and sizing must be done for each ear or performance will be degraded.

4. Compatibility. Must be matched to the user.

5. Readjustment. Since HPDs can work loose, users must be advised of need for 

readjustment.

6. Deterioration. HPDs must be maintained and repaired as necessary.

7. Abuse. Modification of HPDs for comfort which could reduce protection.

8. Removal. When HPDs are not comfortable, they are often removed.

 146 Noise & Hearing Conservation Manual, Fourth Edition (1986). Edited by EH Berger, WD Ward, JC Morrill, and 

LH Royster) pp. 359-360. See also 3M_MDL000774997.

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 EPA - Regulatory Analysis Supporting 

the Noise Labeling Requirements for Hearing Protectors (1979).

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c. Use Requirements/Environment

The purported attenuation of an HPD is not the only factor to consider. “Environmental conditions” 

and “use patterns” are critical. Whether the plug will be used indoors or outdoors is important. If 

indoors, does it account for sound refraction and amplification of surrounding structures? If 

outdoors, will the user be mowing a yard or doing dismounted patrol in the Southwest Asia or the 

Middle East? Will the type of exposure be steady state or impulsive noise from live fire on a range 

or during combat? And, will there be a work helmet or military personal protection or 

communications equipment that may interfere with the protector? In other words, real world 

circumstances are important to consider when developing a particular design of an HPD. 

Laboratory testing under best fit circumstances can test the protector for attenuation but does not 

account for the environment. There is no record evidence that Aearo/3M performed any realworld field studies on their product. A field study performed by the U.S. Army Aeromedical 

Laboratory (USAARL) which did reveal situational awareness problems with the CAEv2 in the 

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nonlinear mode, though USAARL was not examining the CAEv2 for extended wear in real world 

environments through REAT or otherwise.147

a. Fitability

“Fitability” or “fit” relates to the adequacy of a protector in achieving optimum attenuation or 

insertion loss. The design engineer must determine whether the proposed design features are likely 

to fit the contours of the ear canal to gain proper fit.148 A protector should not be designed around 

a filter or certain functionality without accounting for whether it is likely to gain consistent fit that 

a user may achieve in real world circumstances. To engineer a plug for fit, knowledge of the outer 

and inner ear is a prerequisite. As detailed below, Aearo/3M did not undertake any apparent effort 

to engineer the CAEv2 to account for known, variable outer and inner ear morphology and 

dynamics in motion but rather appear to have developed a plug without recognizing the need for 

congruity between the product and the end-user. This would have been reasonable and expected 

of a manufacturer particularly after the receipt of poor attenuation results in Test 213015. 

b. Comfort

In addition to the environment of use and fitability, comfort should be considered when 

designing an earplug. Comfort in earplugs relates to the subjective feedback from a user in terms 

of sensation with a foreign body protector at or beyond the opening of their aperture. Irritation 

and discomfort can be minimized if the materials used are soft and pliable. Introducing a hard 

object into the EC is not optimal for fit or comfort wherein both require a protector to fit the 

contours of the ear. Though comfort and fit/seal are not synonymous, a lack of comfort as 

described in the record from the military should have been an indicator of continued problems. 

c. Biologic Compatibility

The language in EPA (1979) on biologic compatibility is worth quoting here. The EPA 

commission advised: 

The tragus, which is the projection found in front of the external ear, in many individuals 

extends backwards over the ear canal opening, and may prevent the insertion of an insert 

 147 Casali et al. (2009). 148 3M_MDL000774997

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device to its intended depth. The tragus may produce unequal pressure against the 

protective device, forcing the device backward and outward, thus displacing it enough to 

cause an acoustic leak which will reduce the potential noise reducing effectiveness of 

the device.149

The language from Berger and Kieper in the Flange Report is eerily similar:

For test 213015, the plugs were fit according to the standard plug's fitting instructions, with 

no modifications. Because the stem of the green, solid end of the plug is so short; it was 

difficult for the experimenter to insert the plug deeply into some subjects earcanals, 

especially those subjects with medium and larger earcanals. Additionally, the geometry of 

the earcanal opening sometimes prevented the deep plug insertion required for 

maximum attenuation values. When the solid plug was fitted during -the first test (015), 

the basal edge of the third flange of the yellow, level-dependent plug sometimes pressed 

against the subject's earcanal opening and folded up. When the inward pressure on the 

plug was released, the yellow plug's flanges tended to return to their original shape and 

this sometimes loosened the plug, often imperceptibly to the subject.

For test 213017, the yellow flanges of the level-dependent end of the plug were folded back 

prior to the green solid plug being inserted into the subjects' ears. The folded-back flanges 

and the hard plastic stem provided a long stiff quasi-stem for the experimenter to grasp and 

allowed for a deeper and more-consistent fit of the solid plugs for test 213017. When folded 

back in that way, the yellow flanges neither touched the subjects' conchae nor 

compromised the fit of the solid earplugs.

150

The clear language of Aearo/3M’s internal memorandum prepared contemporaneously 

with the 213015 test documents poor attenuation and the likely design features causing fit 

and seal issues. The corrective action, to change the intended form of the protector by 

rolling back flanges to gain better insertion, is not a proper design change. It is an indication 

that there were serious design flaws. Unfortunately, the outer flanges were one among 

several concurrent design flaws that were fatal to its overall design and performance. 

 149 Regulatory Analysis Supporting the Noise Labeling Requirements for Hearing Protectors (1979). EPA, p.24. 150 3M_MDL000019514

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VI. OPINION #1: The CAEv2 was defectively designed in that it contained an inflexible, 

hard, barbed and wide adapter assembly which was positioned deep within the flanged tips 

thereby preventing users from achieving a proper fit, seal and/or cause imperceptible 

loosening compromising continued seal.

a. Additional Chronology of Events and Facts Considered

Between June and July 1997, 3M/Aearo redesigned a prototype of the Nonlinear Ultrafit plug151. 

This redesign changed the filter-stem housing design from the push-pull stem originally suggested 

by Karl Buck in April 1997152 to a twist-knob device that would ultimately become the design 

used in Falco’s 1998 patent153. 3M/Aearo sent the prototype plug, along with related REAT data, 

to ISL for feedback154.

After receiving the new prototype from Aearo, ISL expressed concerns about the stem design,

declaring that “[a] problem which concerns the compulsory unisize requirement of the future 

plugs is the increase in diameter of the prototype plug because of the surrounding stem”. 

(emphasis added).155

ISL added, “We are not at all sure that the present configuration will be suitable for most ears 

because of fitting problems. Should not it be possible to reduce the overall diameter of the stem 

and of the plug (the prototype plug is actually too big)? The external diameter of the filter is 3 mm 

but the outside diameter of the stem at the filter position is 4.2 mm. Is it possible to decrease this 

diameter?”156

On January 19, 1998, 3M/Aearo again updated the adapter design.157 Although the filter-stem 

adaptor configuration of 4.2 mm or greater would cause ‘fitting problems’, the new design had a 

diameter of 4.45 mm at its largest point. See Design Drawing of filter with adapter above. 

b. Thinner CAEv2 prototype (2005)

Knowing the width of the CAEv2’s stem caused comfort issues and that a filter-adaptor housing 

with a diameter greater than 4.2 mm could cause fitting issues, 3M/Aearo began re-designing the 

CAEv2. In January 2005, Elliott Berger asked Bob Falco to produce five new nonlinear filters 

based on the original ISL filter, with varying internal diameters (ID) and lengths (see table below) 

but keeping the original diameter (OD) the same.158 In effect, the walls of the filter were thickened 

to reduce the internal diameter.

 151 The bill of materials for which was then finalized by Marc Doty on July 2, 1997 (3M_MDL000571997). 152 3M_MDL000637265 153 Compare artwork from 3M_MDL000571997 with 3M_MDL000338061. 154 See 3M_MDL000013027 for the response. 155 3M_MDL000013027 156 Id. 157 3M_MDL000393831, page 2. 158 3M_MDL000008580

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Figure 25

The new prototype filters were placed into a CAEv2 and sent to the ISL for testing in March 

2005.159 Based on the test results, Pascal Hamery and Armand Dancer concluded that it seemed 

“possible to reduce the inner diameter (down to 1.25mm?) of the “filters” without impeding the 

performance.”160 They also found that reducing only the length resulted in more attenuation at 

lower frequencies <600Hz161

Figure 26

Given the ISL data, 3M/Aearo drafted a “thin filter” design in May 2005 with an internal diameter 

of 1.75 mm and an external diameter of 2.25 mm while maintaining the original filter length of 

3.72 mm.162

 159 3M_MDL000008548 160 3M_MDL000229352 161 Id. 162 3M_MDL000480972, p.6

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Figure 27

Having reduced the filter’s external diameter, a thinner filter adaptor stem was needed to hold the 

filter and reduce problems caused by the width of the existing filter adaptor.163 The diameter of 

the new adaptor’s widest part was 0.151” or 3.84 mm, smaller than the 4.2 mm diameter mentioned 

by Hamery and Dancer in 1997 and much smaller than the 4.45 mm diameter of the CAEv2. With 

this new adaptor diameter, the diameter of the stem under the CAEv2’s third flange was reduced 

to 0.278” or 7.06 mm.

Figure 28 P2456; 3M_MDL000683454, p.355164

 163 3M_MDL000683454 p.355. See also 3M_MDL000906838, opened using solid works 164 Note: the original length of the adaptor was .588.” This new adaptor is even shorter at .561.”

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Figure 29 3M_MDL000906838

Figure 30 3M_MDL000906838

Despite re-designing the adaptor and filter, producing prototype parts of the filter, and testing 

those parts at the ISL, 3M/Aearo never switched to the thinner CAEv2.

c. CAEv3 (2005-2007), avoiding the previous stem issues. 

1. Changes to the barbed adaptor tip

Initial development of the CAEv3 began in July 2005.165 The CAEv3 was designed to use the 

previously developed “thinner” filter that had the same dimensions as the ISL filter, other than the 

external and internal diameters, 2.25 mm and 1.75 mm, respectively. To avoid the comfort- and 

fitting-related issues of its predecessor, the largest diameter of the barb on the single-ended adaptor 

of the CAEv3 was 4.21mm or 0.166.”166 3M/Aearo not only made the filter and adaptor narrower 

 165 3M_MDL000683454, p.356-360 166 3M_MDL000825888

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compared to the CAEv2, it completely re-designed how the barbed portion of the filter adaptor 

interacted with the CAEv3’s tips. 3M/Aearo also widened the stem of the Ultrafit tips to 5.76 mm 

or 0.227” under the third flange and accounted for a cylindrical void with a diameter of 3.63 mm 

or 0.143” under the third flange of each plug tip167 (small, medium and large). As a result, the 

overall diameter of the stem under the third flange when the filter adaptor was inserted could not 

exceed 6.35mm or 0.250.”168

a. Diameter of the tip of the barbed adaptor 

Figure 31: 3M_MDL000905993169

 167 3M_MDL000481954 168 The total ø under 3rd flange is = L+(-M+N) where L is the diameter of the plug stem without the filter inserted 

.227”, M is the diameter of the out cylindrical void within the plug stem .143”, and N is the diameter of the filter 

stem adaptor at its largest point 0.166.”

169 3M_MDL000905993 – Native file Opened using Solid Works 

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b. Diameter at the widest part of the barbed adaptor. 

Figure 32 3M_MDL000905993170

2. Changes to the length of the adaptor tip

The width of the adaptor in the CAEv2 caused two issues. The primary issue was caused by its

diameter and the secondary issue was caused by its location. The wide barbed tip of the adaptor 

stem is located between 2.36 mm and 5.94 mm into the CAEv2’s stem or directly under the third 

basal flange of the flush Ultrafit tip.

 170 3M_MDL000905993 – Native file Opened using Solid Works

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Figure 33: Falco 2020-02-11, ex.3; 3M_MDL000017774

In comparison, the CAEv3 tips place a cylindrical void into which the adaptor stem barbs can 

protrude between 5 mm and 8.9 mm into the stem.171 This design change effectively doubled the 

space for the interaction points of the barbed-filter housing and the plug’s stem from that of the 

CAEv2, thus avoiding the potential for the widest part of the plugs stem to interact with the 

isthmus. 

Figure: 34

 171 The length of the void is 0.15” or 3.81mm, and the diameter is 0.143” or 3.63mm.

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d. CAEv4 

Like the CAEv3, the Combat Arms Earplug version 4 also used small, medium and large Ultrafit 

tips with a wider stem that, without the stem-adaptor inserted, had an external diameter under the 

third flange of .227” or 5.7 mm. They contained a cylindrical void, molded into the wider tips, 

with a diameter of .143” or 3.63 mm that allowed for variations in the adaptor barb diameter, that 

did not increase the overall diameter of the plug stem. The cylindrical void allowed 3M to increase

the diameter of the barbed-filter housing in the CAEv4 to be larger than CAEv2’s at 0.18” or 4.572 

mm172. However, the same void also ensured that the overall plug-stem diameter under the third 

flange was narrower than the CAEv2 at 0.264” or 6.7 mm. 

Another benefit to this design was that the filter-housing did not protrude as deeply into the plug 

as it did in the CAEv2. The CAEv2’s adaptor extends into the Ultrafit tip by 0.234” or 5.94mm173

. Thus, the length of the Ultrafit unaffected by the adaptor is 0.408” or 10.36mm. The barbed filter 

adaptor for the CAEv4 is 0.346” or 8.78mm. 

• The total length of the Small tip is 0.840” or 21.33 mm174 thus, the length of the plug 

unaffected by the adaptor is 0.494” or 12.52mm

• The total length of the Medium tip is 0.842” or 21.38 mm175 thus, the length of unaffected 

plug is 0.496” or 12.59mm

• For the large, the total length of the tip is 0.854” or 21.69 mm176 thus, the length of 

unaffected plug is 0.508” or 12.90mm

 172 Compare to the 4.45mm in the CAEv2 173 3M_MDL000017774 174 3M_MDL000835381 175 3M_MDL000886489 176 3M_MDL000886488

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177

Figure 35: 3M_MDL000926453

178

Figure 36: 3M_MDL000926453

 177 3M_MDL000926453 - Native file opened using Solid Works. 178 3M_MDL000926453 Native file opened using Solid Works. 

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Figure 37: 3M_MDL000825699

e. CAEV4.1

The Combat Arms version 4.1 is another example of how 3M could have reduced the diameter of 

the plug. At its widest, the portion of the plastic barbed stem of the CAE version 4.1 that is inside 

the user’s ear is .163 inches, or 4.1402mm.179 Compare that to the barbed stem of the CAE version 

2, which, at its widest, is 4.45mm. Importantly, the medium plug for the CAE v4.1180 is the same 

 179 3M_MDL000945476 180 3M_MDL000953715

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as the CAE v2181. The inside diameter of the medium CAE v4.1 plug is .073 inches and the outside 

diameter of the medium CAE v4.1 plug stem is .200 inches.182

Figure 38: 3M_MDL000945476, opened using Solid Works

Figure 39: 3M_MDL000953715, opened using Solid Works

 181 See 3M_MDL000774776 in which J. Ely sends the CAEv4.1 tip drawings to M. Saleem, and see 

3M_MDL000774781 which is the medium plug tip. 182 3M_MDL000953715

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Figure 40: 3M_MDL000953715, opened using Solid Works

Since the diameter of the hole inside the medium CAE v4.1 plug stem is smaller than the plastic 

barbed stem, the outside diameter of the rubber plug stem would expand upon insertion of the 

plastic barbed stem. By adding the difference in size between the inside of the rubber plug stem 

and the widest point of the plastic barbed stem to the outside diameter of the plug stem, we can 

calculate what the maximum size of the CAE v4.1 could have been. At the very most, the CAE v4 

medium size plug could have been .290 inches, or 7.366 mm, wide after inserting the plastic stem. 

By placing the filter in the housing of the CAE v4.1 instead of the stem itself, as had previously 

been suggested by Berger to Dancer and Hamery to reduce the diameter of the prototype Combat 

Arms device.183 3M managed to shrink the overall diameter of the same plug used in the CAE v2 

by 0.120 inches. 

The same calculations can be done for the small and large size plugs for the CAE v4.1. The small 

CAE v4.1 plug stem has an inside diameter of 0.073 in and an outside diameter of .200 inches, 

which are the same dimensions as the medium sized plug;184 as such, the small size plug could 

have been 0.290 inches wide after inserting the barbed plastic stem, just like the medium size plug. 

 183 3M_MDL000013027 at p.2 184 3M_MDL000953714

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The large CAE v4.1 plug stem has an inside diameter of 0.073 inches and an outside diameter of 

0.233 inches at the bottom of the stem,185 which means that the large size plug could have been as 

wide as 0.323 inches, or 8.2 mm, after inserting the barbed plastic stem. Although the large size 

CAE v4.1 plug is larger than CAE v2, the option of using a smaller earplug, namely the small and 

medium CAE v4.1 plugs, means that this diameter, which may be gain satisfactory fit with some 

ear canals, the fact that there is not a “one-size-fits-all" (or most) without sizing options, largely 

takes care of this function of size and fit. 

The CAEv2’s adaptor stem length is 0.234” or 5.94 mm for the CAEv2. However, the 

CAEv4.1’s adaptor stem length is 0.200” or 5.08mm186 meaning that: 

• The small CAEv4.1 tip has a total length of 0.688” or 17.47mm. Thus, the length of the tip 

that is unaffected by the adaptor is 0.488” or 12.39mm

• The medium CAEv4.1 tip has a total length of 0.642” or 16.30mm Thus, the length of the tip 

that is unaffected by the adaptor is 0.442” or 11.22mm

• The Large CAEv4.1 tip has a total length of s 0.739” or 18.77mm Thus, the length of the tip 

that is unaffected by the adaptor is 0.539” or 13.69mm

f. Discussion

For an earplug to protect users, it must conform to the ear canal of the user. The Flange Report 

documents fit and seal problems in a laboratory setting and the lead experimenters concluding that 

”the geometry of the earcanal opening sometimes prevented the deep plug insertion required for 

maximum attenuation values.” 

First, the inner ear structures important to consider in designing an earplug. Inner ear 

measurements and dynamics follow. 

• The aperture is not typically round but oval in shape with a mean range of approximately 

10.0 mm to 15.5 mm in height and 4 mm to 8 mm in width.187

 185 3M_MDL000953318 186 Measured using the natively produced Solid Works file - 3M_MDL000945476 187 Staab, W. J. (2014). “The Human Ear Canal.”

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• The adult EAM, the ear canal extension from the aperture to the eardrum or temporal 

membrane (TM), typically develops a turn or “S” shape, followed by a more tortuous and 

narrowed shape later in life. 

• The EAM is approximately 25 mm superiorly and 30 cm inferiorly188 and is not typically 

a straight body.189

• The isthmus, importantly, has a mean diameter of 5.7mm but ranges in measurement sizes 

between 2.4mm on the smaller end and 9.6 mm on the much larger end. The isthmus has a 

mean height of 9.0mm and ranges between 5.4 mm and 16.5 mm. 

• The isthmus is often the narrowest portion of the EAM, sitting at approximately 9 mm 

inward from the aperture. 

• Depth, shape, hardness and width of the foreign object (plug tip and stem adapter) will 

interact with the inner ear. Where, as mentioned above, the resulting diameter of the 

CAEv2 stem under the third basal flange was 7.6 mm190, including the barbed adapter 

(4.45mm), and whereas the ear canal at or near the location where the mean width narrows 

at a mean of 5.7 mm191, pressure pushing the plug out will increase as the differential 

between orifice and object become greater. Considering that during closed mouth and 

clenched jaw, this dynamic range reduces, to a mean of 4.9mm and 4.3mm, the result is 

more pronounced and concerning. 

• The CAEv2’s linear and nonlinear ends would have been too long, hard, inflexible and 

wide to allow for proper fit, seal and maintain reasonable seal into ears, due to ear canal 

shape, size, morphology, and dynamic behavior.

192

 188 Alvord, L.S., and B. Farmer (1997). “Anatomy and orientation of the human external ear.” Journal of the 

American Academy of Audiology, vol. 8, no. 6, p.383–90; and Alvord, L.S., et al. (1997). “Anatomy of an earmold: a 

formal terminology.” Journal of the American Academy of Audiology, vol. 8, no. 6, p.100–3.

189 See picture below from Ahmad, I., et al. (2001). “External auditory canal measurements: Localization of the 

isthmus.” Oto-Rhino-Laryngologia Nova, vol. 10, p.183–186.

190 X + (Y - Z) where X is the diameter of the barbed filter housing at its widest point (4.45 mm or 0.175”), Y is the 

diameter of the Ultrafit plug (5 mm or 0.200“), and Z is the diameter of the hole born through the Ultrafit plug (1.85 

mm or 0.073“). Compare 3M_MDL000696516 with 3M_MDL000571966.

191 Pirzanski, C.Z. (1997). “Critical factors in taking an anatomically accurate impression.” The Hearing Journal, 

vol. 50, no. 10, p.41, 44, and 46-48; and Pirzanski, C.Z. (2006). “Earmolds and hearing aid shells: Tutorial part 2: 

Impression-taking techniques that result in fewer remakes.” The Hearing Review, 

https://www.hearingreview.com/hearing-products/accessories/earmolds/...ial-part-2-impression-taking-techniquesthat-result-in-fewer-remakes. 192 As described in the report of Dr. Dave Eddins, PhD, testing of the CAEv2 confirms that a significant 

determinative factor in the CAEv2’s failure to gain initial fit and seal and maintain its seal sufficient to provide 

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Second, the inflexibility and width of the final total stem at depths at or nearing dynamic areas of 

narrowing and bending of the EC should have concerned 3M/Aearo. This depth of the wide 

adapter stem would be expected to reach at up to 7 to 8 mm ~ assuming insertion of the inserted 

end is near flush to the EC opening. This depth approaches and involves the reported mean distance 

from the canal opening to the narrowest part of the EC at the isthmus with a mean distance of 9.53 

mm - 9.58 mm. This distance is a mean that does not account for variability. Thus, incongruity 

between a hard adapter and soft cartilaginous segment of the EC more likely than not was the cause 

of the often-repeated discomfort concerns and the push out seen in test 015 documented in the 

Flange Report. Moreover, the EAM are dynamic structures, affected by actions, such as speech, 

chewing, and motions of the head and neck.193 The dynamic nature of the outer ear and EAM are 

highlighted with movement of the mandible (lower jaw) and as the mandible moves forward and 

downward in producing various articulatory and chewing motions, the soft cartilaginous tissues 

along the anterior wall of the EAM are deformed by as much as 2.3 mm.194

Third, the suggestion of a different stem-filter housing configuration by Dancer and Hamery 

should have been considered following the unfavorable initial REAT tests conducted between 

December 1999 and January 2000. Indeed, in 2004, 3M/Aearo contemplated reducing the plastic 

insert’s diameter to improve comfort. Suggested design changes included decreasing the diameter 

of the filter, making the filter an integral part of the hard-plastic insert, or inserting the filter ahead 

of the plastic insert so it would not fit as deeply (P0913A).

 

necessary attenuation and insertion loss protection is the physical and anatomical dimentions of the ear canal along 

with the dynamic movement of the ear canal. See also Staab (2014); Staab, W.J. (2016). “The mysterious 

cartilaginous/bony ear canal.” Canadian Audiologist, vol. 3, no. 6, https://canadianaudiologist.ca/the-mysteriouscartilaginousbony-ear-canal-junction/; and Termeer, P. (1994). Philips Hearing Instruments internal research 

document (cited by W. Staab, 2014). 

193 Oliveira, R., et al. (1992). “A look at ear canal changes with jaw motion.” Ear and Hearing, vol. 13, no. 6, p.464-

6; Oliveira, R.J., et al. (2005). “The dynamic ear canal and its implications.” Hearing Review 

https://www.hearingreview.com/practice-building/practice-management/the-dynamic-ear-canal-and-its-implications. 

The Human Ear Canal, 1995 p. 84-111; Oliveira, R., et al. (2005). Hearing Review. 

http://www.hearingreview.com/2005/02/the-dynamic-ear-canal-and-its-implications/; Darkner, S. (2009). Shape and 

Deformation Analysis of the Human Ear Canal. Thesis. Technical University of Denmark.

194 Darkner, S. (2009). Shape and Deformation Analysis of the Human Ear Canal. Thesis. Technical University of 

Denmark.

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Forth, because the CAEv2 imperceptibly loosens when test-subjects sit immobile in a laboratory, 

as Aearo’s internal REAT testing makes clear, this problem will naturally worsen as users move 

around, talk, chew, or undertake any physical activity. This is especially true for servicemembers. 

This loosening and loss of efficacy as described in the Flange Report is not noticeable to the user 

in the real world. This phenomenon is common and becomes worse in loud environments due to 

the scientific principal called “Just Noticeable Difference” (JND) based on Weber's Law.195 Within 

the branch of psychology called psychophysics, scientist study human perception of external 

stimuli (like noise). One elemental law of psychophysics is Weber’s Law which proposed that the 

level at which a human can perceive quantitative differences in a stimulus is directly proportional 

to its value or magnitude.196 This is called JND. In other words, JND tells us how much, for 

example, noise levels must change to be recognized by the human ear. This is important when a 

person is in a noise hazardous area, like a firing range or traveling in an armored vehicle for short 

durations preparing for potential enemy fire, in that, to know whether a nonlinear ear protector has 

maintained seal becomes increasingly difficult in loud environments. Knowing this in either the 

linear or nonlinear end is very challenging and a soldier would not typically be able to perceive 

subtle differences sufficient to be warned of this loosening or slippage of the CAEv2. In the 

nonlinear end, this would be even more challenging.

With low attenuation of the yellow end of the CAEv2 at low frequencies from 125 Hz to 500 Hz 

provides the basis for a very difficult to improbable detection of a change of sounds at the ear as 

the plug loosens and loses insertion loss. The plug is not providing any attenuation at these 

frequencies and therefore the perception is the same with the plug in or nearly out. Unfortunately, 

an overall 5 dB change in the attenuation/insertion loss of the plug results in a 10x change in the 

number of allowable shots using the criteria in MIL STD 1474D. For an example, if 200 shots 

were the maximum allowable number of shots with a fully inserted CAEv2 then only 20 shots 

would be permissible with a loosened CAEv2 that had only lost 5 dB of attenuation or insertion 

loss. The CAEv1 chosen by the French, German and Belgian militaries offered this option. JND 

for an untrained listener is 3 dB. However, with the CAEv2 having basically 0-10 dB of 

 195 Weber's Law of Just Noticeable Difference, University of South Dakota: 

http://apps.usd.edu/coglab/WebersLaw.html

196 Pedrielli et al., (2008). “Just noticeable differences of loudness and sharpness for earth moving machines.” The 

Journal of the Acoustical Society of America, vol. 123, no. 5, p.1-6. 

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attenuation at the low frequencies, if working as intended, the plug could easily move enough to 

cause a 5 dB or larger loss of attenuation while the perception of the sound would change very 

little and not be perceived in non-laboratory environments. Indeed, military field conditions with 

hazardous noise exposure include: small-arms fire weapons training; tactical live-fire training; 

dismounted patrol; convoys, helicopter flights and other travel in military personnel carriers and 

aircraft; walking, running, jumping and other physical movement across varying obstacles and 

terrain; and other activities in warm environments or close quarters with surrounding elements.

Fifth, most earplugs are made exclusively with softer materials that conform to the curvature and 

shape of the ear canal. After all, every ear canal is different. The CAEv2’s white plastic insert was 

made out of Delrin—a plastic known for its tensile strength and stiffness. Its manufacturer, 

Dupont, describes Delrin as “the ideal material in parts designed to replace metal.” Because of 

Delrin’s stiffness, it cannot conform to the curves and contours of various ear canals. Instead, it 

maintains its shape, thereby preventing it from conforming to any ear canal, other than one that is 

straight. A direct outcome from a lack of congruity between the CAEv2 and soldiers’ ear canal 

morphology is a lack of comfort. Berger proposed a pair of possible solutions when redesigning 

the CAEv2. These solutions addressed previously observed problems, namely that the CAEv2’s 

hard plastic stem that was too short and the acoustic filter too wide, thus requiring a larger stem 

diameter to accommodate the ISL filter. Both of these problems could adversely affect comfort 

and insertion depth within ear canals. 

A review of soldiers’ feedback of the CAEv2’s confirms that there were comfort issues that 

soldiers identified after using the CAEv2.197 Berger’s own proposed solutions to enhance comfort 

and fit included using the longer Euro-design of the combat arms plug in order to reduce the stem’s 

width requirement, and lower the cost of the product, or have two products available in different 

sizes.198

 197 For 3M’s early knowledge of comfort issues related to the CAE v2 and its design, see Aearo / 3M employee 

Robert Falco’s patent for the UltraFit plug (No. 4,867,149 (1989)), p.3; and 3M_MDL000017328 p.1. 

198 3M_MDL000192859

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VIII. Opinion #2: The CAEv2 was defectively designed because its opposing flanges were 

too close to the inserted flanges, precluding users from achieving a proper fit and seal 

and/or causing imperceptible loosening that compromised continued seal.

The design, or redesign as it were, of the CAEv2 pushed the adapter deeply on both ends of the 

plug. This moved the outer flanges closer to the opposing flanges as well. The Flange Report 

documents Aearo’s observations of high variability and poor fit and seal and attributed the 

presence of opposing flanges in the tested subjects which caused imperceptible loosening. This is 

a mechanism of concern which would likely have caused sufficient outwardly force to compromise 

fit and seal. A starting point would be to describe the relevant outer ear structures important to 

consider in designing an earplug like the CAEv2 which had dual ends. These include the auricle 

or pinna, tragus, anti-tragus, and concha. 

Figure 41

It was well known and established prior to the design of the CAEv2 that outer ear elements, like 

the tragus, can be involved in the insertion of a plug and prevent insertion to an intended depth. 

The tragus can also produce unequal pressure against the protective device, forcing the device 

backward and outward, which can displace the device enough to cause acoustic leaks and reduce 

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the potential noise reducing effectiveness of a device.199 These and other outer ear structures are 

susceptible to displacement and deformation during jaw movements (Darkner, 2009). The 

resulting defects diminished CAEv2’s effectiveness and increased variability in fitting the CAEv2 

for the individual user. If an earplug design fails to account for ear morphology and the dynamic 

nature of the ear canal, this incongruity can cause air leaks due to lack of fit, initial seal, and 

continued seal.

As with Opinion #1 above, the effect of the presence of outer flanges complicated insertion and 

resulted in imperceptible loosening. Unfortunately, this creates, again, the challenge of being able 

to self-check for a loose plug. The hear-through capabilities of the CAEv2, which may have not 

been optimal,200 would still have made it difficult for users to know whether the plug was properly 

sealed to the ear. Indeed, according to Hamery and Dancer of ISL, the French military evaluated 

the CAEv2 and found it difficult to ‘verify if the plug is well fitted’.201 Unfortunately, where the 

CAEv2 was known to imperceptibly loosen, no prompt is provided to the user to adjust the plugs. 

For that reason, French military rejected the CAEv2 and instead used a single-sided plug that 

allowed soldiers to occlude the nonlinear end with a finger-tip to check for proper seal. With the 

CAEv2, no method exists to perform this check. A situation where this may occur is during 

dismounted patrol. In the presence of some background noise, the CAEv1 could be readily 

occluded. And, to restate an important point germane to a soldier’s use of the CAEv2, where a 

soldier may want to check seal may be on the gun range where sound levels may reach the inner 

ear between 110-140 dBP.202 At these higher levels, a soldier is not able to perceive a drop in 5 or 

10 dB which can make all the difference. 

 199 Regulatory Analysis Supporting the Noise Labeling Requirements for Hearing Protectors (1979), EPA. See also 

report of Dave Eddins. 

200 See Casali and Ahroon (2009). 201 3M_MDL000003061 at p.70 202 A review of internal 3M emails however raises a concern that the CAEv2 should never have been used on a range 

in the nonlinear "impulse” side. See 3M_MDL000243859, 3M_MDL000359112, 3M_MDL000473499, 

3M_MDL000010140, and 3M_MDL000392992.

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IX. Opinion #3: The CAEv2 was defectively designed because the location of the ISL filter, 

stem, and adapter assembly created unintended and potentially harmful standing 

resonance at high frequencies.

In 1997, Dancer documented stem and/or filter resonance and communicated this problem to 

Berger.203 Multiple studies of the CAEv2 have since revealed strong resonance at higher 

frequencies. Such resonance causes users to experience increased excitation and potentially high 

to ultra-high frequency hearing loss or other auditory injury.204

This peculiar resonance pattern is not evident in other brands of LDNL HPDs.205 Binseel et al. 

(2012) attributed this high-frequency resonance property to resonance vibrations of the solid 

portion of the protruding linear end of the CAEv2; it would appear that the location of the filter in 

relation to the total length of the sound channel and stem effects this resonance independent of the 

residual air cavity or ear canal resonance effect at a higher frequency.206 Subsequently, Fedele 

and Kalb (2015) reported that the CAEv2’s nonlinear end produced the same prominent highfrequency resonance pattern in IL measurements to impulse noise.207 Unfortunately, 3M 

engineered a resonance in the CAEv2 in a frequency band (~5-7 kHz) where the ear is sensitive 

to damage. The design placement of the filter is more likely than not the cause. There does not 

appear to be any supporting engineering analysis, however, movement of the filter back away from 

the tip would have helped dampen the standing resonance. The result is additional hearing damage 

risk due to what appears to be a casual approach to design changes and the neglect of good 

engineering practice.

The record evidence does not reflect that Aearo/3M undertook any examination or effort to 

investigate findings of Drs. Dancer and Hamery relating to resonance which was identified in 

 203 3M_MDL000013024 204 For more on this, see 3M_MDL000002569, DOD Touhy Production Document Touhy00001927, Binseel (2012) 

“A Comparison of the Single-Sided and Double Sided Combat Arms Earplugs,” Scharine and Weatherless (2014) 

“U.S. Marine Corps Level-Dependent Hearing Protector Assessment - Objective Measures of Hearing Protection 

Devices,” and 3M_MDL000009125. 

205 See 3M_MDL000002569, DOD Touhy Production Document Touhy00001927, Scharine and Weatherless 

(2014), and 3M_MDL000009125.

206 Binseel (2012) 207 3M_MDL000009125

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1997. In 2012, scientists at the Army Research Laboratory published a report that documented 

resonance attributable to the CAEv2. This was followed by a study in 2015 which further 

documented ARL’s finding of a resonance characteristic that appeared to be describe a standing 

wave of resonance that was linked to the plug. Of note, the resonance discussed by ARL is a 

standing wave resonance at around 6-7 kHz (similar to that described at 6.2 kHz by Fedele et al.) 

which described as an amplitude-dependent nonlinear characteristic.”208 A review of the Report 

in this case of Steve Armstrong further confirms this acoustic property associated with the CAEv2. 

The figure by Kalb et al., showing two resonant peaks, one in normal auditory arrange, is 

remarkably similar in location and as that generated from high fidelity Berkley Spice Simulation. 

This effect can present risk to a user exposed to impulsive noise of auditory damage. 

Figure 10 - Armstrong Report

 208 Fedele, P, Kalb, J. Level-Dependent Nonlinear Hearing Protector Model in the Auditory Hazard Assessment 

Algorithm for Humans. ARL-TR-7271 (2015), p 19. (origins of the resonance described as possibly from the 

protruding end of the CAEv2 or from within the orifices in the plug at p 31).

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Figure 9 - Armstrong Report

Armstrong concludes the resonance is due to “the combination and configuration of the length of 

the sound channel, distance to the end of the earplug tip, and filter location within the sound 

channel.”209 In reviewing the ARL papers and confirmatory work by Armstrong, it is reasonable 

to conclude that the location of resonance is likely due to the placement of the filter in closer to 

the middle of the adapter stem. Movement of the filter would tend to dampen this phenomenon 

that appears to be specific to the CAEv2. Importantly, this standing resonance results in a 

reasonable conclusion that soldiers and users exposed to weapons fire and other impulsive noise 

would experience cochlear injury at high or ultra-high frequencies. Though audiograms in the 

military typically test up to 6 kHz and would not show noise induced hearing loss at higher 

frequencies, it is recommended that audiogram testing be sought to more fully determine 

potentially overlooked auditory injury. 

X. Opinion #4: In addition to these design defect opinions, I have the following opinion 

with regard to their compliance which the terms of the MPID:

a. MEDICAL PROCUREMENT ITEM DESCRIPTION (MPID) 2003, revised 2006

In 1999, 3M/Aearo secured the U.S. Department of Defense, Defense Logistics Agency’s 

acceptance of the CAEv2 without any actual testing of the product in its dual ended configuration. 

 209 Armstrong Report at 

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3M/Aearo secured an NSN number and the CAEv2 was placed on the Approved Product List. 

3M/Aearo commenced sales of the plug the same year. All of this was achieved without a formal 

contract ostensibly under a provision of the Defense Acquisitions process enabling manufacturers 

or sellers of commercially available products the ability to begin sales without a formal request to 

all manufacturers to bid on producing a product that met particular requirements and 

specifications. However, by 2003, and again in 2006, the Defense Logistics Agency (DLA) did 

require 3M/Aearo to adhere to an MPID covering some aspects of the CAEv2. Those parts 

addressed herein are: 

1. As to 2003 and 2006 MPIDs regarding testing, the sampling for inspection at 

100% on the nonlinear yellow end to be “verified by an acoustical impedance 

test”210; 

2. As to 2006 MPID regarding testing and efficacy, the sampling for inspection at of 

the linear green end under ANSI/ASQ Z1.4 (inspection level S-2) with AQL of 

1.0%211; and

3. As to 2006 MPID regarding efficacy, that the CAEv2 would provide the “user” 

with “protection” at sound pressure levels up to 190 dBP, even after the user has 

been exposed to 100 free-field noise impulses of 190 dBP, minimum. 

b. MPID – “verified by an acoustical impedance test”

3M/Aearo has been using an Acoustic Resistance Checker (ARC) (or Z-Box) in their laboratory 

since 1989. It has used the device with plugs such as their Ultratech-12 and ER-20. It was chosen 

by 3M/Aearo unilaterally to test impedance for all CAEv2. (Kieper and Berger, 2000b). 

Commonly called an “ARC device”, the same was invented by and purchased from Etymotic 

Research. The purpose of the device is to test acoustic resistance or impedance. An ARC machine 

 210 The author understands that 3M was required under MPID 2003 and 2006 to retain all “records of inspection” for 

a period of 3 years after delivery of the earplugs, including 3M/Aearo subsidiary or sub-contractor TJR/ATM, and 

that records relating to impedance testing and quality control were not made available potentially due to 2 year 

retention policy. 

211 Having requested documents in the litigation that would reflect that 3M/Aearo and 3M consistently met their 

quality assurance requirement of performing REATs under the ANSI/ASQ Z1.4 requirement, and having reviewed 

the deposition testimony of A. Childress, it appears that 3M/Aearo and 3M did not make any attempt to ensure the 

quality of the plugs they sold to the military for closed end linear protection.

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functions by measuring the opposition that a system presents to the acoustic flow resulting from 

an acoustic pressure applied to the system. An ARC box measures resistance in terms of mV. To 

set up an ARC box it is necessary to ‘block the input tube with Duxseal, a malleable, clay-like 

substance and apply a 100Hz, pure tone signal to the unit of sufficient voltage (~380mV) to obtain 

200mV AC out. (Kieper and Berger, 2000b). Once the set-up has been verified, the desired product 

may be tested on the Arco box, be that to develop acceptable ranges for it or to ensure that it meets 

already established ranges.

In August 1999 (3M_MDL000755464) before 3M/Aearo had performed any REAT or impulsive 

testing on the CAEv2, it added the ARC testing to the Standard Operating Procedure for the 

Combat Arms Assembly – SOP 227. 

In September 2001 3M/Aearo, through Elliott Berger, assured Major Mark Little that 3M/Aearo’s 

conduct quality checks using an acoustic impedance device to assure that the plugs have been 

assembled properly’, that the filters are in place and ‘that the dimensions of the orifice fall within 

our specifications’(3M_MDL000251776).

When reviewing the first MPID in February 2003, 3M/Aearo, via Bryan Myers, changed the 

language in the Sampling for Inspection section to “Sampling shall be 100% for the “yellow” level 

dependent end. It shall be verified using an acoustical impedance test”. Ten minutes after the last 

modification was made to the document by Bryan Myers, he informed John Komada at the Defense 

Logistics Agency (DLA) via email that ‘We consider the “acoustical impedance test” under the 

“Sampling for Inspection” paragraph to be proprietary”. (P1356A 3M_MDL000257850).

3M/Aearo view as to the proprietary nature of the 100% ARC testing was once again raised by 

Myers during discussions with personnel from the DLA. This time, Myers informed Thomas Sidor 

of the DLA that ‘we have developed a special test fixture we use to test every Combat Arms 

earplug which we make. This test assures that the filter is properly made and assembled into the 

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earplug so that when a very loud noise occurs, the earplug will function properly.’ (P0364 

3M_MDL000018856).

The exact specifications for the nonlinear filter developed by the ILS was for two plate-like filters 

with a thickness of 0.1mm (0.004”) and an orifice of 0.3mm (0.012”) separated by an internal 

distance of 3.52mm (0.138”). The device is 3mm in diameter and 3.72mm in length. 

Seven different variations of the plate thickness and orifice diameter were tested using SPLs at 

110 dB, 130dB, 150dB, 170dB and 190dB. It was found by researchers at the ISL that a platefilter with a thickness of 0.1mm (0.004”) and an orifice of 0.3mm (0.012”) offered “an optimum 

nonlinearity” among all of the tested plate configurations. (Hamery et al. 1997) 

In Figures 17a and 17b from the R128/97 report by Hamery (below) one can observe, just as the 

creators of the filter did, that if the plate thickness is off by 0.05mm (0.001”) the attenuation 

coefficient can vary by up to 4dB at NRpeaks over 110db. Similarly, one can observe that if the 

diameter of the orifice of the plate-filter is altered by 0.1mm (0.004”) the attenuation can be altered 

by up to 3dB at NRpeaks over 110dB.

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Figure 17a e= Thickness d= Diameter 

Figure 17b e= Thickness d= Diameter

3M/Aearo was aware of these specifications when drafting their own technical drawing of the filter 

in 1998. 3M/Aearo’ draftsperson, Marc Doty, specified in his technical drawing that the filter 

dimensions had to be produced in such a way as to equal the ISL-designed nonlinear filter, and 

could only deviate from said dimensions by ±.0004” (or ± 0.01mm). Doty’s specifications match 

the design specifications 3M/Aearo received from ISL in February 1997212. 

 212 3M_MDL000476896

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 213

Unusually, despite knowing the importance of both the filter-plate thickness and orifice diameter 

as of February 1997, 3M/Aearo seemingly chose to ignore the specification for the filter-plate 

thickness when performing their first article inspection214 on June 2nd 1999215. 

 213 Compare 3M_MDL000755095 left with 3M_MDL000825751 right. 214 The first article inspection is a process through which one measures each individually manufactured part to verify 

that the parts received match the specifications laid out in the technical drawings. 

215 3M_MDL000010303

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Failure to meet these exacting specifications could have negative consequences, as one can clearly 

see from Figures 17a and 17b from R128/97 (above). A failure to ensure that the product part met 

its exacting specifications could mean that said part, and thus entire plug assembly, was out of 

specification which could result in a drop of up to 3dB to 4dB of attenuation at Sound Pressure 

Levels in NRpeaks of over 110dB. 

3M/Aearo knew how critical it was to meet these specifications and that a failure to do would 

have unknown consequences especially with regards to the protective attenuation that the filter 

could provide to the user of the device in which it is placed. Due to this knowledge, in 2003, 

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3M/Aearo sent back an initial order of around 400,000 to 500,000 filter parts to the vendor in 

France as they were found to be ‘bad’216.

Unfortunately for the users of the 3M/Aearo’s passive nonlinear products, in June 2004 3M/Aearo 

once again discovered that the filters they had been purchasing from the part manufacturer, Roland 

Bailly, were out of specification. Out of 42 production samples chosen, only 10 met the orifice 

diameter specification meaning that 76% of the randomly selected filter parts were out of 

specification.217

Despite the continuous filter problems, 3M/Aearo continued to purchase the filter for their 

nonlinear product from Roland Bailly in France. 3M/Aearo had to ship a further 200,000 

Nonlinear filters back to the product manufacturer to be refunded as they failed to meet the design 

specifications (3M_MDL000825799). 3M/Aearo ultimately changed the exacting specifications 

for the nonlinear filter that ISL provided to them, moving the allowed tolerances from ±.0004” (or 

± 0.01mm) to ±.0005” (or ± 0.013mm) (3M_MDL000886406)

218

 e = Thickness d=Diameter

 216 3M_MDL000855229 217 3M_MDL000930590 218 3M_MDL000009240 

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c. ARC Testing problems

Despite how important 3M/Aearo represented the ARC testing to be, they failed to address a 

plethora of issues that caused the Combat Arms to deviate from the acceptable ranges laid out in 

the specifications for the Combat Arms on each respective ARC box. In fact, in February 2003, 

while 3M/Aearo was actively discussing the proprietary nature of the testing and adding language 

as to how they sample and test 100% of the plugs, they were also attempting to address an “80% 

rejection rate” at their Mexico assembly plant. 

"RWK assisted Gordon Grogan and spoke with Bob Zielinski about the problems with the Combat 

Arms Plug in Mexico. He recommended that one of the ARCs be sent to Indianapolis so the 100 

plugs can be measured in the lab, to help determine why Mexico’s measurements had an 80% 

reject rate" (RK-132, p. 148)

In his February monthly memo, Berger reported the same “80% reject rate” that was found at TJR 

using the CAE and ARC devices (DK-015, p.2). In May 2003, Kieper reported that he had to recalibrate ARC devices and said, “After I ‘calibrated’ (verified that its output was the same as it 

was 2 years ago) one of the four Acoustic Resistance Checkers (ARC) that have been made for 

EAR/Aearo, I sent the unit back to Mexico . . . . Somehow, the two calibration plugs (blocked

tubes) that [were] made for the 2 Mexican units were lost” (RK-416, p.1)

This issue of ARC testing at TJR worsened between 2003 to 2004, and on November 8, 2004, 

Zielinski expressed concern that TJR “cannot get any ‘acceptable’ product from the calibrated 

tester” because the measurements “are all too high according to the specs” (RK-412, p.1). This 

issue was concerning to 3M/Aearo and 3M because without proper calibration, there was no way 

for 3M/Aearo to confirm that the plugs meet quality standards or that they will work as advertised.

A week later on November 19, 2004, Klun circulated an action plan to address the quality problems 

at TJR (RK-405; RK-406). This plan shows that the ARC devices had not been calibrated even 

after a full year and that 3M/Aearo / TJR had to operate “under a waiver for over six months” to 

address “back order issues . . . . Because of equipment measurement problems, TJR continues to 

operate with a quality waiver” (RK-406, p.2). According to this action plan,

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“it has taken over six months to address equipment calibration problems for the Combat Arms 

product. Now we have more quality testing problems and releasing product under waiver. We 

believe this issue is not an acute problem, but rather a chronic problem that needs to be fixed now. 

We need team perspective to take a holistic look at the combat arms quality program at TJR” (RK406, p.2)

During the 2004 holidays, Kieper traveled to Mexico to implement the action plan. Berger reported 

in his December monthly report: “Upon RWK’s return from Mexico work continued to resolve 

testing issues for this product including a call with Etymotic. At month’s end we were also 

requested to obtain a quote for an additional z-box (no order placed yet)” (DK-100, p.2).

Needless to say, Aearo/3M understood the importance of (and promised) a quality testing program 

to assure the yellow level-dependent end of the plug would provide the insertion loss required for 

impulsive noise for users. An Acoustic Resistance Checker (ARC), the test was considered critical 

in determining efficacy yet the government appears to have been never apprised of serious 

problems with the testing setup, process and procedure, input/output data, presence and prevalence 

of out of specification results, provision of waivers and other information to make a judgment as 

to the quality of ear protector the government was receiving. Documents and testimony relating to 

quality testing program reveal significant problems with the testing devices and plugs testing well

out of quality specification ranges. This appeared to occur whether the ARC boxes were 

purportedly properly calibrated, mis-calibrated, or uncalibrated; and whether the testing occurred 

in Mexico or Indianapolis. At one point, over 80% of plugs were reported as having tested out of 

specification, however, there is no documentation revealing that the government was made aware. 

Critically, it is of utmost importance that ear protectors sold to our soldiers be quality products 

which are tested and go through quality assurance. Where Plug dimensions can alter impulsive 

noise protection, allowing our soldiers to receive plugs that are suspect in their quality is 

problematic to say the least.

d. MPID - testing and efficacy, the sampling for inspection of the linear green end 

under ANSI/ASQ Z1.4

As mentioned, there is no documentary evidence establishing that 3M/Aearo ever satisfied this 

MPID requirement. Accordingly, it failed its obligations to the government. 

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e. MPID - protection of soldiers for up to 100 blasts at 190 dBP

The French No.1 plug was not the final CAE v2 that 3M/Aearo sold to the US military. BOP did 

not test the CAEv2. P2416. However, over the lifecycle of the CAE v2, 3M/Aearo’s have used the 

BOP as scientific evidence for the marketing claim that the CAE v2 was “found to be protective 

at 190dB for at least 100 exposures” (3M_MDL000153471, p.2). Indeed, 3M audiologist Ted 

Madison testified that “The Johnson study was the basis for the claim about 190 decibels” (P2417; 

Madison, 12/10/2019, 343:19-20). 

On July 16, 2006, the final version of the MPID #2 was published stating that 3M/Aearo would 

provide the military an earplug designed to “provide protection at sound-pressure levels up to 190 

dBP (peak), even after the user has been exposed to 100 free-field noise impulses of 190 dBP 

(peak), minimum” (P0101; Berger 30b6, 11/13/2019, ex.29; 3M_MDL000000078). 

On February 8, 2010, Berger questioned the scientific basis of 3M/Aearo’s protection claim for 

the CAE v2. Berger emailed Ohlin and 3M’s Military Marketing Manager Doug Moses to ask 

where the claim that the CAE v2 was “found to be protective at 190dB for at least 100 exposures” 

came from and if it went “back to the Blast Overpressure Study in Nevada” (sic) 

(3M_MDL000153471, p.2). Berger received confirmation that the claim derived from the BOP.219 

Berger replied that the data from the BOP was not sufficient to prove 3M’s claims. Berger pointed 

out that “with 100 shots there was 20% failure from 178-187, 50% failure at 190 and no tests 

allowed at 193” (ibid., p.1). Berger also said he remained “unconvinced” that the BOP could 

support 3M’s claim because “the ISL plug in this study use[d] a filter about the same as the one 

we produce” but “its mounting in the plug is different as is the length of the plug” compared to the 

CAE v2 that 3M was selling” (ibid.). 

Despite Berger’s objections to using the BOP as support for the 190dB protection claim, 3M 

continued to misrepresent the results of the BOP when touting the safety of the CAEv2. For 

example, a brochure for the CAEv2 and v4 dated September 23, 2010, continued to use the 190dB 

claim (3M_MDL000012058, p.2). 

 219 Id. 

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By December 2012, 3M’s partner New Dynamics was also using the 190dB claim on marketing 

materials despite 3M’s internal knowledge that the claim was false. The promotional materials for 

the CAE v2 from New Dynamics state that the CAE v2’s “level-dependent technology used in the 

earplug has been tested and found to be protective up to approximately 190 dBP for outdoor 

exposures” and cite the BOP as support (3M_MDL000749309, p.2). 

On July 9, 2014, Madison affirmed Berger’s comment from 2010 that the “CAEs will not reduce 

190dB explosions to a safe level of 140dB or less” (P0148; 3M_MDL000008470, p.2). Berger 

noted prior on July 8, 2014 in a reply to Jason Jones:

“The CAE does not provide 30 dB peak reduction for a 140 dB peak. The plug in the 

open mode provides from 10-12 dB reduction at 130 dB, increasing to about 20-30 dB or 

more for 170 dB, depending on the nature of the impulse. The data below are from ISL. 

We get similar but not identical results in our impulse test lab. The data that show that the 

plug provides adequate protection at 190 dB are from a US Army study conducted with 

soldiers in the early 1990s. They found for a limited number of blasts up to about 190 dB 

the plugs prevented temporary threshold shifts. However, those were large weapons with 

much low frequency content. For rifle shots that are more hazardous to the ear because of 

their high-frequency content the protection will not be as great.”

Instead of proving 3M/Aearo’s protection claims for the CAE v2, the BOP shows that there was 

insufficient data to determine if the ISL filter inserted into Aearo’s UltraFit plug provided adequate 

protection. For example, Johnson wrote that “not enough subjects were exposed to provide a 

definitive answer” regarding whether the ISL filter “performed better” than the other nonlinear 

plug (P0164B, p.144). Moreover, Johnson concluded that “[w]ith the limited number of subjects,” 

the French no.1 plug was not “adequate to protect the auditory system from” the large weapons 

fire that subjects were exposed to (ibid., p.3). Finally, Johnson wrote that during testing, “There 

was concern that good seal of the flanges with the ear canal was not occurring for some subjects” 

and that the investigator “could not distinguish between the intentional leak through the filter and 

leak around the flanges” (ibid., p.33).220 NATO’s RTO Technical Report “Hearing Protection –

Needs, Technologies and Performances” evaluates different types of earplugs in the context of 

military sound. The study explains that nonlinear earplugs provide little attenuation for moderate 

 220 Both Henning von Gierke and Edgar Shaw developed electrical/mechanical analogs of earmuff attenuation. 

However, the 1st order parameter driving earmuff attenuation is the size of the acoustic leak. The approach for 

improving passive attenuation with earplugs was similar to the approach for earmuffs. i.e. reduce and/or eliminate 

the acoustic leak.

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level sounds and should perform similarly to their linear counterparts when exposed to highest 

level sounds (4-12-13). Fit also becomes paramount to the functionality of the earplug as “[i]n the 

case of a misfit of the plug, the non-linear behavior will be lost” (4-14).

In summary, the BOP test and resulting data relied upon by Aearo/3M in making the 190 dBP 

claim, was insufficient as a reasonable basis upon which to make such an assertion. A liberal 

reading of the BOP study would support a statement that some subjects utilizing plug with 

nonlinearity qualities did not exhibit temporary threshold shifts after exposure to up to 6 blasts at 

approximately 190 dBP. However, BOP involved the French singled ended version not the CAEv2 

and the results were not supportive of this claim. 3M/Aearo do not appear to have undertaken 

any further scientifically valid efforts to support their claim.

Furthermore, using the scientific measurements conducted by ISL during the design of the filter, 

it can be seen that the size of the orifice and the thickness of the plate are critical parameters in the 

acoustic performance of the filter: specifically, the insertion loss; and changes in the insertion loss 

with increasing peak pressure. Good engineering practice would establish the mapping of these 

two parameters to the measured acoustic performance of the filter as installed in the CAEv2 and 

would use a consistent and validated method to measure this performance during production. From 

the data available, it appears that 3M did not anchor nor tie the acoustic performance of the yellow 

end of the CAEv2 to the production measurements made with the ARC. Therefore, there was no 

validation of the acoustic performance of the yellow end of the CAEv2 achievable from the ARC 

measurements. Additionally, the ARC measurement, due to calibration and measurement issues, 

exhibited significant uncertainty further exacerbating the issue of verifying acoustic performance 

of the CAEv2 during production. The government was buying a hearing protector that was 

intended to have acoustic performance sufficient to protect the hearing of soldiers. Yet, 3M chose 

not to verify the acoustic attenuation or insertion loss of the CAEv2 during production. Even the 

limited requirements of the MPID were not met and 3M did not inform the government that the 

CAEv2 earplugs being delivered did not meet the MPID requirements.

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XI. SAFER ALTERNATIVE DESIGN:

When evaluating safer alternative designs for a HPD, many of the factors from the Noise & 

Hearing Conservation Manual concerning Real World Performance of HPDs are relevant in 

making the evaluation. Simply reviewing REAT numbers to determine whether a device is a safer 

alternative design would be inappropriate. This is particularly true where one is looking at 

experimenter fit data, which attempts to show optimal performance versus real world performance 

where actual users wear the HPDs for extended periods of time. Factors that are often overlooked 

in evaluating HPDs include, but are not necessarily limited to:

1. Comfort. Crucial in the real world as it involves compliance.

2. Utilization. Earplugs may be incorrectly inserted or adjusted.

3. Fit. This must be done for each ear or performance can be affected.

4. Compatibility. Must be matched to the user.

5. Readjustment. Since HPDs can work loose, users must be advised of need for 

readjustment.

6. Deterioration. HPDs must be maintained and repaired as necessary.

7. Abuse. Modification of HPDs for comfort which could reduce protection.

8. Removal. When HPDs are not comfortable, they are often removed.

Noise & Hearing Conservation Manual, Fourth Edition (1986)(edited by EH Berger, WD Ward, 

JC Morrill, and LH Royster) pp. 359-360.

Thus, when evaluating safer alternative designs, one must consider not only what characteristics 

an HPD possesses but also what it lacks. In addition, should an HPD possess a certain negative 

characteristic, whether the manufacturer has attempted to mitigate against the negative 

characteristic should be factored into the equation. By way of example, the Combat Arms Version 

4.1 has a “retainer clip” which, according to its marketing materials “helps the earplug stay in the 

ear during rigorous activity.”221 It specifically notes that: “A specially designed patented soft 

retainer helps ensure the ear plug remains securely seated inside the ear.” Thus, for this earplug 

at least, 3M determined there was an issue with the plug staying “in the ear during rigorous 

activity” and addressed that issue.

 221 3M_MDL000766967

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The following posters provide reference points for hearing protectors approved for use in our 

military. Making the Approved Product List does not ensure a safe and effective plug. The CAEv2 

is proof of that. However, the family of plugs providing both linearity and nonlinearity that exist 

today (and have existed since circa 2008 and beyond) all have very similar design characteristics 

and noise attenuation and continuous noise attention qualities. The current offering has not 

changed considerably since 2015, except that the CAEv2 is notably “discontinued” by 2015. The 

second figure is from the Hearing Center of Excellence (2018). 

Figure 41

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Figure 42

List of Safer Alternative Designs:

• CAEv1 for impulsive noise protect and hear through ability for situational 

awareness AND an Ultraflex-type plug for continuous noise protection

• CAEv4 for both impulsive and continuous noise protection with hear through 

ability for situational awareness 

• CAEv4.1 for both impulsive and continuous noise protection with hear through 

ability for situational awareness 

• Surefire Sonic Defender EP4 (triple flange) for both impulsive and continuous noise 

protection with hear through ability for situational awareness 

• Moldex Battleplug for both impulsive and continuous noise protection with hear 

through ability for situational awareness 

a. CAEv1 for impulsive noise protection and hear through ability for situational 

awareness AND an Ultraflex-type plug for continuous noise protection

A great deal of discussion has been had on the CAEv1. It was the genesis of later CAE family of 

protectors. It was utilized by NATO allies. It was clearly a safer alternative to the CAEv2 and 

was available in 1999 and beyond. 3M/Aearo could have selected the CAEv1. Specifically, 

linear and nonlinear end tips which became the CAEv2 ends were already designed and in use by 

Aearo/3M. A detailed description is below. These tips were also tested by Aearo/3M and the 

NRR attenuation numbers were known. Those NRR tests contained data which included 

attenuation at frequency. That information, along with the derived NRRs, provided a baseline for 

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the tips. When Test 213015, memorialized in the Flange Report, was performed, the suboptimal 

and poor attenuation data was revealed. Aearo/3M, Aearo/3M was on notice of the great 

disparity in results and should have undertaken good manufacturing and design measures under 

ISO 9001:1994. The government did not have this information necessary to make a good 

decision on proceeding with the CAEv2. 

b. CAEv2: Utilization of Pre-existing Ultrafit and Ultraflex-type plugs 

3M/Aearo utilized Ultrafit tip (yellow end) and UltraFlex tip (green end) for the CAEv2.222 A 

picture of the final design drawing for the CAEv2 is below which includes both tips (yellow 

nonlinear identified as segment ”A” and green linear identified as segment ”B”). 

(Figure 43 Berger 30(b)6 2020-09-25, ex.2, 3M_MDL000017774, page 11)

 222 See Berger 30(b)6 2020-09-25 Tr. 25:4-26:6.

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i. Nonlinear (yellow) UltraFit Tip for Impulsive Noise

Since 1989, 3M/Aearo had a preexisting patent for the UltraFit (yellow) tip and did not complete 

the final designs for the CAE v2 until ten years later in 1999.223 Aearo’s designer Robert Falco 

patented the UltraFit,224 and the company used this design to create earplugs using the UltraFit 

plug with through hole, including the UltraTech or Hi Fi earplug.225 The important difference 

between the UltraTech and the final CAE v2 was the hard plastic adapter stem that 3M/Aearo 

chose to use in the design of the CAE v2.226

The diameter of the adapter stem made the CAE v2 unsuitable for most ears because of fitting 

problems. 3M/Aearo was aware that the hard adapter stem created issues in the design and 

performance of the CAE v2 yet chose to move forward with this problematic design. In 1997, ISL 

investigator’s Armand Dancer and Pascal Hamery updated Berger about their concerns with the 

prototype filter used in a modified UltraFit tip. According to Dancer and Hamery, the “increase in 

diameter of the prototype plug because of the surrounding stem” would lead to “fitting problems” 

and advised “reduc[ing] the overall diameter of the stem of the plug” from its current diameter of 

“4.2 mm.”227 Despite ISL’s concerns, 3M/Aearo not only used a large design for the diameter of 

the adapter stem but also increased the size to 4.45 mm in the final designs of the CAE v2 (See 

figures below).228 The NRR testing for the UltraFit and UltraFlex tips showed positive results 

during Aearo’s and ISL’s testing. For example, in 1997, ISL reported that the “EAR UltraFit 

earplug . . . has good attenuation performances.”229 These results prompted ISL to move forward 

using the UltraFit tip to house ISL’s filter.

ii. Linear (green) UltraFlex/Ultrafit Plus Tip for Continuous Noise

In 1997, the same year that ISL reported its findings for the UltraFit tip, 3M/Aearo performed 

REAT testing for the UltraFlex tip used as the green end of the CAE v2. A picture of the final 

 223 Id. at 31:12-19. 224 U.S. Patent No. 4,867,149 225 Berger 30(b)6 2020-09-25 Tr. 50:22-51:4. 226 Id. at 65:2-24. 227 Berger 30(b)6 2020-09-25, ex.13, page 1 228 Berger 30(b)6 2020-09-25, ex.2, page 9 and 11

229 Berger 30(b)6 2020-09-25, ex.7, page 26

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design drawing for the CAEv2 is below which includes both tips (the original tip of the UltraFlex 

and the final modified UltraFlex tip is identified as Figures 44 and 45, respectively).

Figure 44: Page 9 of ex.2; Drawing 2041-1 for CAE v2

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Figure 45: Page 11 of ex.2; Drawing 2041-3, final design of the CAE v2

3M/Aearo used the UltraFlex tip in the design for a semi-aural band device. According to Aearo’s 

internal REAT testing, the UltraFlex band showed an NRR of 27.4, 24.2, and 24.1.230 Berger 

affirmed that the NRR testing for the UltraFit and UltraFlex tips showed positive results and that 

the REAT results for the UltraFlex band were actually higher than the REAT results for the green 

end of the CAE v2 tested two years later.231 It is significant that key differences between the 

UltraFlex band and the CAE v2 green end are the stem and adapter: the UltraFlex band did not 

have the rubber stem shortened unlike the CAE v2 and the UltraFlex band did have an adapter that 

was of a different shape and a lower diameter than the adapter used in the CAE v2. 

 230 Berger 30(b)6 2020-09-25, ex.16, 17, and 18 231 For the UltraFit, see Berger 30(b)6 Tr. 85:22-24, and for the UltraFlex, see id. at 192:4-193:15. For Berger’s 

confirmation regarding the REAT results for the CAE v2 and UltraFlex band, see id. at 196:5-14.

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Aearo’s design modifications to the UltraFlex end of the CAE v2 caused the fitting problems 

addressed in the Flange Report related to the length of the green end. The Flange Report indicates 

that “[b]ecause the stem of the green, solid end of the plug is so short; it was difficult for the 

experimenter to insert the plug deeply into some subjects’ earcanal openings, especially those 

subjects with medium and larger earcanals.”232 According to Aearo’s internal design drawings, the 

UltraFlex tip was longer at first than the final design. A preliminary drawing dated March 24, 

1998, by 3M/Aearo designer Marc Doty shows that the UltraFlex tip for the CAE v2 used 

specifications from drawing 2032-B (See also figure below).233 Aearo’s final design drawings 

show that the company used drawing 2068-0 dated April 27, 1999, as the final design for the 

UltraFlex tip (Berger 30(b)6 2020-09-25, ex.2).234 The adapter stem for the preliminary design of 

the green end does not push down as deeply into the UltraFlex tip compared to the final design 

that pushes into the back of the largest flange.

 232 3M_MDL000019514 233 Berger 30(b)6 2020-09-25, ex.14 234 Berger 30(b)6 2020-09-25, ex.2. Berger affirmed that the preliminary designs for the UltraFlex tip showed a 

longer length than what 3M/Aearo used in its final designs for the CAE v2 (see Berger 30(b)6 2020-09-25 Tr. 

181:8-22).

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Figure 46: Preliminary design drawing for the CAE v2 with longer UltraFlex length

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Figure 47: Final CAE v2 drawing with shorter UltraFlex length

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Figure 48: Drawing 2068-0: Final design drawing for the UltraFlex (green) tip for the CAE v2

3M/Aearo had the option to use a more flexible alternative design for the CAE v2 adapter. For 

instance, the UltraFlex band tested in 1997 used an adapter that connected between the arm of the 

band and the UltraFlex tip of the plug using a rounded ball of 0.75 inches (See also figure 

below).235 According to Berger, the material used to design the adapter for the UltraFlex band is 

“more flexible than the material that is the stem adapter in the Combat Arms 2.”236

 235 Berger 30(b)6 2020-09-25, ex.15, page 2. Berger affirmed the difference between the UltraFlex band adapter and 

the CAE v2 adapter (see id. at 189:16-23). The adapter that pushed into the opening of the UltraFlex used a thin 

diameter close to the end and gradually became wider to the point where it connected to the band leg.

236 Id. at 201:24-202:1

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Figure 49: Berger 30(b)6 2020-09-25, ex.15, UltraFlex adapter

3M/Aearo had preexisting earplugs that the company could have used as safer alternative designs 

for the CAE. As discussed earlier, the designs for the UltraFlex semi-aural band completed in 1997 

predated the Flange Report published internally in July 2000.237 In addition, all REAT testing for 

the UltraFlex band was completed in 1997 prior to the first REAT test for the CAEv2 completed 

in January 2000.238 Additionally, the designs and testing of the UltraFit Plus, another safer 

alternative design using the UltraFlex tip, were completed prior to the publication of the Flange 

Report and the 213015 REAT testing for CAEv2 green end. Both the UltraFlex band and UltraFit 

Plus showed better NRR results than the CAEv2 (see figures below). Both the UltraFlex and 

UltraFit Plus provided steady-state noise protection sufficient for continuous noise protection.

 237 See Berger 30(b)6 2020-09-25, ex.15. 238 See Berger 30(b)6 2020-09-25, 16, 17, and 18 and 3M_MDL000019514. 

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Figure 50: image from 3M website239

Figure 51: image from packaging of UltraFit Plus240

By March 1999, 3M/Aearo began designing an alternative earplug using the UltraFlex tip called 

the UltraFit Plus.241 3M/Aearo used drawing 2068-A, the identical tip design as the green end of 

 239 3M E-A-Rflex Hearing Protector with UltraFit Tips, https://www.3m.com/3M/en_US/company-us/all-3mproducts/~/3M-E-A-Rflex-Hearing-Protector-with-UltraFit-Tips-350-1100-100-EACase/?N=5002385+3294755211&rt=rud) 240 Berger affirmed this NRR in his testimony (see Berger 30(b)6 2020-09-25 Tr. 245:24-246:4). 241 See id. at 227:24-228-23.

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the CAEv2, for the final design of the UltraFit Plus.242 The UltraFit Plus was an available safer 

alternative design to the CAEv2. Although both plugs used the same UltraFlex tip, the UltraFit 

Plus had a longer, more flexible stem than the CAE v2, did not have opposing flanges that caused 

the plugs to loosen imperceptibly like the CAE v2, and was not a dual-ended design. In addition, 

the Ultrafit does not suffer from the characteristic of a hard plastic Delrin stem, which is too stiff, 

too wide, and too uncomfortable to allow for proper fit and seal. This is supported by the fact that 

REAT testing on the Ultrafit earplugs consistently supports higher NRR for the Ultrafit over the 

CAEv2.

The final design drawings for the UltraFit Plus show that the stem of this earplug was made from 

a flexible vinyl material called Unichem Vinyl (See also figure below).243 However, the CAEv2 

was designed with a shorter, more rigid adapter stem. Although 3M/Aearo had the ability to 

produce plastic stems that were more flexible, the company went with a defective design for the 

CAEv2’s adapter stem.244

The REAT tests for the UltraFit Plus also demonstrate that that plug design achieved better NRR 

results than the green end of the CAEv2 even though the UltraFlex tip for both plugs is identical. 

On July 7, 1999, when 3M/Aearo began marketing the CAEv2, 3M/Aearo completed REAT 

testing for two sizes of the UltraFit Plus.245 This testing for the UltraFit Plus occurred six months 

before 3M/Aearo conducted REAT testing on the CAEv2.246 3M/Aearo reported that one test 

subject had failed and that the original NRR was 24.3 and without the failed subject, the NRR was 

26.1. The subjects for both the REAT test of the UltraFit Plus and the green end of the CAEv2 

were the same. However, the NRR’s for the green end of the CAEv2 during the first test of the

plug were dramatically lower: the green end of the CAEv2 averaged a mean NRR of 14.5 while 

the UltraFit Plus averaged a mean NRR of 28.7.247

By 2004, Berger admitted that one of the primary problems with the CAEv2 was the hard, 

inflexible adapter stem and concluded that an alternative design was necessary for the product. In 

 242 Id. at 231:19-232:8. 243 Berger 30(b)6 2020-09-25, ex. 21. See also Berger 30(b)6 2020-09-25 Tr. 238:8-15. 244 Id. at 256:23-257:1. 245 Berger 30(b)6 2020-09-25, ex.22 246 Berger 30(b)6 2020-09-25 Tr. 244:20-245:8 247 See 3M_MDL000019514 (Flange Report) for the results of the first REAT testing of the CAEv2 green end.

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an email to Doug Ohlin from November 15, 2004, Berger stated that a “principal reason for 

discomfort is the plastic insert in the earplug stem”.248 Berger said that a potential solution would 

be to reduce the diameter of the filter. Berger’s proposal to Ohlin in 2004 is the same advice that 

Dancer gave to Berger in 1997 before the CAEv2 was sold to the military with its defectively 

designed stem.249 The CAEv2 was not a suitable design for most ear canals because of the plastic 

insert that when fitted deeply caused problems with comfort and fit.

Figure 52: Berger 30(b)6 2020-09-25, ex.19, prototype UltraFit Plus

 248 Berger 30(b)6 2020-09-25, ex.23

249 Berger 30(b)6 2020-09-25 Tr. 260:6-19

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Figure 53: Berger 30(b) 2020-09-25, ex.20, final UltraFit Plus

Figure 54: Demonstrative used in Berger 30(b)6 2020-09-25

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Figure 55: Berger 30(b)6 2020-09-25 UltraFit Plus Stem

In summary, the above chronology and detail of Aearo’s design engineering missteps appear to 

reflect a company eager to sell a novel product to the military on the promise of offering benefits 

not previously provided by a protector.250 No matter the motivation, technology existed which 

would have provided our soldiers linearity and nonlinearity in two separate plugs. The CID 

investigation respondents resoundingly affirm that the CAEv2 would not have been chosen were 

 250 For 3M documents pertaining to sales of the CAE, see 3M_MDL000492909, 3M_MDL000260838, 

3M_MDL000020026, 3M_MDL000153514, 3M_MDL000184852, and 3M_MDL000110105.

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the failings memorialized in the Flange Report made known.251 As the Garinther memo at 

Aberdeen reflects, option number 1 of two separate plugs was offered. The ISL or CAEv1 plug 

did not have the adapter and flange problem. It would have been safer and effective for impulsive 

noise. For linearity, the 3M/Aearo Ultrafit and Ultraflex product lines that existed then, and exist 

today, would have been adequate and certainly presented a safer and effective plug for continuous, 

steady state noise protection.

C. OTHER NONLINEAR EARPLUGS 

1. CAEv4 for both impulsive and continuous noise protection with hear through 

ability for situational awareness 

3M/Aearo could have sought to develop the CAEv1 with a stitch or twist mechanism that we now 

find in the CAEv4, CAEv4.1, Surefire Sonic Defender and the Moldex Battleplug. All of these 

products do favorably and do not have the uniquely problematic characteristics of the CAEv2 that 

were well known to 3M/Aearo. They are all safer alternatives to CAEv2. The CAEv4 ultimately 

replaced the CAEv2 with an improved single-ended CAEv4 plug design incorporating a rocker 

switch to achieve better user mode switching while wearing the CAEv4 plug.252 The new CAEv4 

plug design housed the nonlinear acoustic filter within the outermost portion of the stem along 

with the rocker-cap switch assembly. Both components were placed external to the opposite-end 

stem portion fitted with one of three sizes (small, medium, or large) of triple-flange ear tips. The 

CAEv4 was evaluated by 3M/Aearo from 2007-2009 and, subsequently, was offered to the 

military to replace the CAEv2 dual-ended plug.253 The CAEv4 remains on the APL.

The CAEv4.1 is a safer alternative to the CAEv2 The CAEv4.1 is an example of 3M’s continued 

efforts to improve upon the CAEv4. It has a thin stem and the filter moved away from the ear 

canal. It has an earlock to lessen any movement or slippage. In addition, a later version of the 

CAEv2, the CAEv4.1 has a “[s]oft, flexible retainer clip helps the earplug stay in the ear during 

rigorous activity.” Again, the retainer clip addresses a problem with the CAEv2 known to 3M: 

 251 For instances of this, see the Army’s criminal investigation report: CID_FILE0001: David Zarenkiewicz (p.35), 

James Johanson (p.36), Brian Schott (p.37-38), Albert Gatica (p.214), Mark Anthony (p.222), John Komada (p.225), 

and Joel Bealer (p.238-39). 252 3M_MDL000203825 253 Id.

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imperceptible loosening. It is fitted with one of three sizes (small, medium, or large) of tripleflange ear tips. 

2. Surefire Sonic Defender EP4 (triple flange) for both impulsive and continuous noise 

protection with hear through ability for situational awareness

Figure 56

The EP4 is a safer alternative to the CAEv2 and is on the APL. Among features available that are 

beneficial to a user, they include a method of preventing loosening of an earplug through use of 

an ear lock or retainer clip. The lock utilized has seven grab points (Fig. 56) in the concha bowl. 

Importantly, the EP4 has an ergonomically curved stem. The Earlock moves around the first turn 

and up to and past the isthmus. The EP4 is sold in sizes small, medium and large. These are an 

important and addresses two inherent problems with the CAEv2: comfort and imperceptible 

loosening. The EP4, which utilizes a Hock filter with a modification on the open/close mechanism. 

Colonel Grantham tested the EP4 to determine IPIL and compared those results against results on 

the CAEv2 obtained at Aberdeen Proving Ground at a prior date. The comparison was favorable 

to Surefire which was granted entry into the APL. Additional points of interest in comparing the 

Surefire include, that: that 3M/Aearo conducted an internal comparison of the CAEv4 (the new 

and improved CAE version) against the EP4254 and it was determined that EP4 was of a softer 

material and had an ergonomic stem that bends to help facilitate placement in the ear canal and 

that REAT analysis performed in furtherance of gaining approval on the Approved Product List 

 254 3M_MDL000198782

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revealed that the EP4 did better than the CAEv2 in impulsive noise except at high dBP above 

160~.255 

3. Moldex Battleplug for both impulsive and continuous noise protection with hear 

through ability for situational awareness 

The Battleplug is a safer alternative to the CAEv2 and is on the APL. Like the CAEv4, it is single 

ended without the adapter stem design found on the CAEv2 and without opposing flanges. The 

Battleplug is sold in sizes small, medium and large. These are important and addresses two 

inherent problems with the CAEv2: comfort and imperceptible loosening. The EP4, which utilizes 

a Hock filter with a modification on the open/close mechanism. Additional points of interest in 

comparing the Surefire include, that: 3M and ISL performed impulse noise testing on the CAEv4 

and BattlePlug using an acoustical test fixture, and determined that the BattlePlug had “almost the 

same nonlinear behavior [as] the Combat arms earplug.”256 The BattlePlug is a single-ended, 

triple-flanged earplug that uses a “cap” mechanism on the non-inserted end to switch between 

linear and non-linear modes.257 

4. Custom Molded Products 

Custom molded products with or without nonlinearity are and were safer alternatives to the

CAEv2. Custom earplugs minimized the size of acoustic leaks by improving fit.258 Custom 

earplugs also improve reliability of fit as evidenced by a reduced standard deviation in attenuation 

scores, and, with custom earplugs, a factor that was beneficial was that they were comfortable in 

comparison to inserted earplugs.259 Throughout the time CAEv2 was sold to the military, custom 

molded products were available on individual basis. The custom molding enables a user to insert 

a non-linear filter such as the Hocks filter used in the Surefire EP4. Military Hearing Conservation 

Program directives allowed for the Service Member to opt into a custom molded choice and, 

knowing what is known presently about the CAEv2 design defects, a custom molded choice would 

 255 3M_MDL000395009 256 3M_MDL000098869.

257 3M_MDL000358819 258 McKinley, RL, Bjorn, VS, Hall. JA (2005) Improved Hearing Protection for Aviation Personnel. In New 

Directions for Improving Audio Effectiveness (pp.13-1 -- 13-12). Meeting Proceedings ROT-MP-HFM, Paper 13, 

Neuilly-sur-Seine, France: RTO, p 13-6.

259 Id. at 13-7 -- 13-8.

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have enabled impulsive noise protection along with situational awareness. This product is formed 

to a user’s ears taking out the biocompatibility challenges that protectors can pose in some users. 

CONCLUSION

All of the above opinions are held to a reasonable degree of professional and scientific 

certainty. They are based to a reasonable degree of professional probability and on scientifically 

reliable evidence. I reserve my right to amend or supplement my opinions if further information is 

provided in any form including, but not limited to, corporate documents, depositions, and expert 

reports.

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EXHIBIT A

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 113 of 171
Resume

(October 2019)

1. NAME: Richard L. McKinley

2. POSITIONS:

Oct 2019 – Current

F-35 Senior Acoustics SME

Booz Allen Hamilton

Beavercreek, OH 45431

July 2016 – Oct 2019

F-35 ORISE Acoustics SME

Oak Ridge Institute for Science and Education

Battlespace Acoustics Branch, Warfighter Interface Division

Human Effectiveness Directorate, Air Force Research Laboratory

Wright-Patterson Air Force Base, OH 45433-7901

May 1976 – Jun 2016

Principal Biomedical Engineer, DR-IV

Battlespace Acoustics Branch, Warfighter Interface Division

Human Effectiveness Directorate, Air Force Research Laboratory

Wright-Patterson Air Force Base, OH 45433-7901

3. EDUCATION:

M.S. Communications/Signal Processing, Air Force Institute of Technology 1986

B.S. Biomedical Engineering, Vanderbilt University 1975

4. MEMBERSHIP ACTIVITIES IN PROFESSIONAL AND TECHNICAL 

SOCIETIES:

Fellow – Air Force Research Laboratory 2010-2016

Fellow - Acoustical Society of America 1996-present

American National Standards Institute (ANSI), Working Group S3-36, 

Speech Intelligibility Tests for Evaluation of Communications Equipment

 1997-present

ANSI, Working Group S12.35, Speech Communications while Wearing Hearing 

Protectors 1998-present

ANSI, Working Group S12.10, Hearing Protectors 1987-present

ANSI, Chair, Working Group S1.15, Noise Canceling Microphones 1990-present

ANSI, Chair, Working Group S12.53, High Performance Aircraft Noise 

Measurement 2009-present

ANSI, Chair, Working Group S1.12 Measurement of Sound Pressure 

Levels in Air 2019-present

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Resume – Richard L. McKinley page 2

August 2019 

Air Force Representative to Accredited Standards Committees S1 on Physical 

Acoustics 1988-2016

Air Force Representative to Accredited Standards Committees S12 on Noise

 1990-2016

Air Force Representative to Accredited Standards Committees S3 on Bioacoustics

 1993-2016

National Academy of Sciences Committee on Hearing, Bioacoustics and 

Biomechanics 1977-1992

5. HONORS AND PREVIOUS AWARDS:

DOD Standardization Program Award – MILSTD 1474E Noise Limits 2015

AFRL 711th Human Performance Wing Scientific and 

Technical Achievement Award (Team) 2014

F-35 Program Office Senior Civilian of the Year 2013

Fellow – Air Force Research Laboratory 2010

AFOSR Star Team Award – Excellence in Basic Research – Bioacoustics 2002, 2009

Joint Strike Fighter Team Award 2009

Joint Strike Fighter Civilian of the Quarter 2008

Fitts Human Engineering Award 2007

Mission Support Award (Team) 2001

Director’s Award 1999

Fellow Acoustical Society of America 1996

Total Quality Leadership Award 1994

Air Force Systems Command Aerospace Primus Award for

 Outstanding Research Engineering Contributions 1991

Harry G. Armstrong Award for Scientific Excellence 1990

 Air Force Systems Command Scientific Achievement Award 1987

 Air Force Systems Command Scientific Achievement Award 1982

 Air Force Systems Command Scientific Achievement Award 1980

 Outstanding Performance & 1981

 Sustained Superior Performance(&/or cash 

award)1985,1987,1988,1989,1994,1995,1996

6. SIGNIFICANT ACCOMPLISHMENTS:

SIGNIFICANT ACCOMPLISHMENTS:

- ANSI S1.13 -2020 American National Standard Measurement of Sound Pressure 

Levels in Air 2020

- ANSI S3.71 American National Standard Methods for Measuring the 

Effect of Head-worn Devices on Directional Sound Localization in the

Horizontal Plane 2019

- ANSI S12.76 American National Standard Methods for Measurement of 

Supersonic Jet Noise From Uninstalled Military Aircraft Engines 2017

- F-35A operations in a Hardened Aircraft Shelter 2016

- MILSTD 1474E – Noise Limits 2015

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Resume – Richard L. McKinley page 3

August 2019 

- F-35A and F-35B Ground Run-up and Flyover Noise 2013

- ANSI S12.75 High Performance Aircraft Noise Methods 2012

- ANSI S12.42 Hearing Protector Objective Performance Methods 2011

- Joint Strike Fighter Ground Run-Up and Flyover Noise Test 2008

- Joint Strike Fighter Jet Blast Deflector Non-Linear Acoustic Effects 2003

- dB Towers 3-D aircraft acoustic signature range – concept & basic design 2002

- DoD Improved Hearing Protection for Aviation Personnel Plan (DTO) 2001

- Joint Strike Fighter Vibroacoustics Lead 1997

- Combined Auditory/Visual Search & Detection Experiments 6. 1 grant 1995

- Total Quality Leadership Award 1994

- ILIR - Fiber Optic Microphone development 1993

- AFSC Primus Award for Outstanding Research Engineering 1992

- Harry G. Armstrong Award for Scientific Excellence 1990

- Nominated AFSC Civilian of the Year 1988

- Awarded Long Term Full Time Training 1988

- Interior Acoustics and Speech Intelligibility for VC-25 (AF-1) 1987

- Nominated for Armstrong Award 1981, 1988

- Nominated for Arthur S. Fleming Award 1983

- Conceived and obtained funding for dB Towers 2003

- Sponsored JSF – AFRL/HE Days 2002

- Assembled, managed, and led Navy-Air Force sub-IPT for Joint Strike Fighter 

- Conceived and obtained funding for SOF C-130 ANC program 1997

- Program Manager; SBIR Fiber Optic Microphone Development 1993

- Bioacoustics and Biocommunications Laboratory MCP Design 1985

- Lead Technical Engineer; Tri-service Communications Audio

Distribution System 1984-1990

- Active Noise Reduction Technology development 1978-present

- Non-Linear Acoustic Propagation 2003

- ANR and 3-D Audio for F-35 Joint Strike Fighter Program 2001

- Joint AF-Navy Development of Improved Hearing Protectors 2001-2016

- 3-D Audio for Navy F-18 program 1998

- Developer of JSF vibroacoustics joint service program 1997

- Developer of tri-service enhanced noise reduction working group 1996

- Development & Flight test of 3-D audio in AV-8B for JAST 1995

- Developed Voice Communications Effectiveness Task 1993

- Developed Voice Communications Jamming Model 1991

- F-22 Pilot and Maintainer noise requirements and measurement 1990-2000

- Principal investigator on two AFOSR intra-mural research efforts 1995-2000

- Successfully established new in-house research facilities:

Auditory Localization Facility 1990

Hearing Protector Assessment Facility 1989

Performance and Communication Research and 

Technology 1989

Active Noise Reduction Measurement Facility 1987

- Developer of Auditory Localization Cue Synthesizer 1987

- C-130 Active Synchro-phaser for Noise Reduction 1985-1990

- B-2 Cockpit Acoustics/Pilot noise and communications 1985-1989

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August 2019 

- B-1 Cockpit Acoustics/Pilot noise exposure 1980-1990

- Developer of Active Noise Reduction Headset Technology 1980

- Voice Communications Research and Evaluation System 1980

7. PATENTS AND PUBLICATIONS:

McKinley, R.L., Driesen, Major A.L. van Veen, T.H., Wall, A.T., van ‘t Hof, J., 

Graafland, F., Gibney, D.M. Corbett, T.A. Block, M.J., Ott, D.K., Jackson, TSGT J.M.,

Flory, L.E., and Miller, J.E., Environmental Parameters of F-35A Operations in a 

Hardened Aircraft Shelter at Leeuwarden Royal Netherlands Air Force Base, F-35 Joint 

Program Office, October 2016.

Murphy, W. J., Jerome, T. W., Gallagher, H. L., Theis, M. A., and McKinley, R. L.,

Comparison of Three Noise Reduction Rating Calculators for Passive and Active Hearing 

Protection Devices, EPHB Report No. 360-13a, July 2015.

A. T. Wall, K. L. Gee, T. B. Neilsen, B. M. Harker, S. A. McInerny, R. L. McKinley, and 

M. M. James, “Investigation of multi-lobed fighter jet noise sources using acoustical 

holography and partial field decomposition methods,” AIAA Paper 2015-2379, June 22-

26, 2015.

B. O. Reichman, J. M. Downing, A. Aubert, R. McKinley, K. L. Gee, T. B. Neilsen, A. 

T. Wall, and M. M. James, “Acoustical Environment of an F-35B Aircraft During 

Vertical Landings,” AIAA Paper 2015-2377, June 22-26, 2015.

M. M. James; A. R. Salton; J. M. Downing; K. L. Gee; T. B. Neilsen; B. O. Reichman; R. 

McKinley; A. T. Wall; H. Gallagher, “Acoustic Emissions from F-35A and F-35B 

Aircraft during Ground Run-Up,” AIAA Paper 2015-2375, June 22-26, 2015.

Gallagher, H.L., McKinley, R.L., Theis, M.A., Swayne, B.J., Thompson, E.R., 

Performance Assessment of Passive Hearing Protection Devices. AFRL-RH-WP-TP2014-0148, 2014.

Wall, A. T., and McKinley, R. L., “New American National Standard: Methods for the 

measurement of noise emissions from high performance military jet aircraft,” Proc. 

Noise-Con 2014.

Gee, K.L., Neilsen,T.B., Muhlestein, M.B., Wall, A.T., Downing, J.M., James, M.M, and 

McKinley, R. L., On the Evolution of Crackle in Jet Noise from High-Performance 

Engines, 19th AIAA/CEAS Aeroacoustics Conference, May 27-29, 2013, Berlin, 

Germany, AIAA 2013-2190.

Gee, K. L., Neilsen, T. B., Downing, J. M., James, M. M., McKinley, R. L., McKinley, 

R. C., and Wall, A. T., "Near-field shock formation in noise propagation from a highpower jet aircraft," J. Acoust. Soc. Am. 133, EL88-EL93 (2013).

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August 2019 

Gallagher, H.L., McKinley, R.L., Noise Attenuation Performance of the Joint Service 

Aircrew Mask (JSAM) Fixed Wing Variant with Flight Helmets. AFRL-RH-WP-TR2013-0015, 2013.

Gallagher, H.L., McKinley, R.L. (2012) Noise Attenuation Performance Assessment of 

the Joint Helmet Mounted Cueing System (JHMCS). AFRL-RH-WP-TR-2012-0174, 

2012.

Aubert, A., McKinley, R.L., Measurements of Jet Noise Aboard US Navy Aircraft 

Carriers, AIAA Centennial of Naval Aviation Forum “100 Years of Achievement and 

Progress”, Sep 2011, AIAA 2011-6947.

McKinley, R.L., Hearing and Noise, Chapter 1.5 in, Handbook of Aerospace and 

Operational Physiology, Woodrow, A. and Webb, J.T., editors, USAF School of 

Aerospace Medicine Special Report (SR), AFRL-SA-WP-2011-0003, Aug 2011, pages 

1-56 to 1-68.

McKinley, R.L., McKinley, R.C., Computation of Community Noise Contours

Relative to Operations of F-35 Aircraft, F-35 Lightning II Joint Strike Fighter Program 

Office Technical Report, Aug 2011.

Gallagher, H.L., Bjorn, V.S., and McKinley, R. L., Attenuation performance of double 

hearing protection devices, Acoustical Society of America, POMA Volume 11, pp. 

040005 (August 2011).

James, S.H., et al, Hearing Protection – Needs, Technologies and Performance, NATO 

Technical Report, RTO-TR-HFM-147, Nov 2010.

McKinley, R.L., Spyropoulos, J., Munro, S., Proposed Standard 3-D Aircraft Flyover 

Noise Measurement And Analysis Methods, Proceedings of 16th AIAA/CEAS 

Aeroacoustics Conference (31th AIAA Aeroacoustics Conference), Stockholm, Sweden, 

Jun 2010, AIAA-2010-4003.

McKinley, R.L., McKinley, R.C., Gee, K., Pilan, T., Mobley, F, Gillespie, M, and 

Downing, M., Measurement of Near-Field and Far-Field Noise from Full Scale High 

Performance Jet Engines, Refereed Proceedings of the ASME Turbo Expo 2010: Power 

for Land, Sea and Air, Glasgow, UK, June 14-18, 2010, GT2010-22531.

Vold, H., Shah, P., Davis, J., Bremner, P., McLaughlin, D., Morris, P., Veltin, J., and 

McKinley, R., High-Resolution Continuous Scan Acoustical Holography Applied to 

High-Speed Jet Noise, Proceedings of 16th AIAA/CEAS Aeroacoustics Conference (31th 

AIAA Aeroacoustics Conference), Stockholm, Sweden, Jun 2010, AIAA-2010-3754.

Abel, S., Baudou, J., Bjorn, V., Buck, K., De Boodt, F., Drullman, R., Henry, P., James, 

S., McKinley, R.L., Sarafian, D., Van Der Veken, P., Hearing Protection - Needs, 

Technologies, and Performance, NATO RTO TG-147 Final Technical Report, April, 

2010. 

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August 2019 

McKinley, R. L., Auditory and Acoustic Research & Development at the Air Force 

Research Laboratory, Acoustics Today, Acoustical Society of America, Jan 2010.

Murphy, W. J, et al, Results of the National Institute for Occupational Safety and

Health—U.S. Environmental Protection Agency Interlaboratory

Comparison of American National Standards Institute S12.6-1997 Methods A and B, 

pages 3262-3277, J. Acoust. Soc. Am. Vol. 125, No. 5, May 2009

Hobbs, B, Hudson, D, King, M, McKinley, R, Brungart, D, Wideband Hearing, 

Intelligibility, and Sound Protection (WHISPr), AFRL-RH-TR-2009-31, Oct 2008

McKinley, R.L. 60 Years of Hearing Conservation and Hearing Protection Research and 

Development at Wright-Patterson Air Force Base, Council for Accreditation in 

Occupational Hearing Conservation (CAOHC) Update, Fall 2007.

McKinley, R.L., Preliminary Assessment of Damage Risk Associated with F-35 JSF 

Transparency Removal System (TRS), Joint Strike Fighter Program Office, Arlington, 

VA, 2006.

McKinley, R.L., Hobbs, B, Brungart, D.S., NACRE Quiet-Pro Earplug Performance 

Study, Marine Corps Systems Command, Quantico, VA, 2006.

McKinley, R.L., Kordik, A., Dancer, A. Loudness Matching in Bone/Tissue Conducted 

Noise, Proceedings Internoise 2005, Aug, 2005.

Hall, J.A., McKinley, R.L., New Directions for Custom Earplugs, Proceedings Internoise 

2005, Aug, 2005.

McKinley, R.L., Bjorn, V.S., Hall, J.A., Improved Hearing Protection for Aviation 

personnel, NATO RTO-MP-HFM-123 New Directions for Improving Audio 

Effectiveness, April 2005

Ericson, M. A., Simpson, B. D., & McKinley, R. L., 3-D Audio: Military Applications and 

Symbology NATO HFM-123 New Directions for Improving Audio Effectiveness, April, 

2005

Ericson, M.A. Simpson, B.D. and McKinley, R. L. Military Speech Communication over 

Vocoders in Tandem, NATO HFM-123 New Directions for Improving Audio 

Effectiveness, April, 2005

Bjorn, V.S., Albery, C.B, Shilling, R, McKinley, R.L., U.S. Navy Flight Deck Hearing 

Protection Use Trends: Survey Results, NATO HFM-123 New Directions for Improving 

Audio Effectiveness, April, 2005

Simpson, B.D., Brungart, D.S., Gilkey, R.H., McKinley, R.L., Spatial Audio Displays for 

Improving Safety and Enhancing Situation Awareness in General Aviation 

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August 2019 

Environments, NATO HFM-123 New Directions for Improving Audio Effectiveness, 

April, 2005

Simpson, B. D., Bolia, R. S., McKinley, R. L., and Brungart, D. S., The impact of hearing 

protection on sound localization and orienting behavior. Human Factors, 47(1), 188-198.

2005.

Brungart, D. S., Simpson, B. D., McKinley, R. L., Kordik, A. J., Dallman, R. C., & 

Ovenshire, D. A., The interaction between head-tracker latency, source duration, and 

response time in the localization of virtual sound sources. Proceedings of the 10th

Meeting of the International Conference on Auditory Displays, 2004.

Brungart, D. S., Kordik, A. J., Simpson, B. D., & McKinley, R. L., Auditory 

localization in the horizontal plane with single and double hearing protection. Journal of 

the Acoustical Society of America, 112, 2244, 2003.

Brungart, D. S., Kordik, A. J., Simpson, B. D., & McKinley, R. L., Auditory localization 

in the horizontal plane with single and double hearing protection. Aviation, Space, and 

Environmental Medicine, 74, 937-946, 2003.

Simpson, B. D., Bolia, R. S., McKinley, R. L., and Brungart, D. S. Sound localization 

with hearing protectors: Performance and head motion analysis in a visual search 

task. Proceedings of the 46th Annual Meeting of the Human Factors and Ergonomics 

Society 105:1024, 2002.

McKinley, R.L., McKinley, R.C., and Mobley, F, Measured Flyover Noise Levels and F35 Predicted Flyover Noise Levels, JSF Program Office, Arlington, VA, Nov 2003.

Brungart, D. S., Kordik, A. J., Simpson, B. D., & McKinley, R. L., Auditory Localization 

in the Horizontal Plane with Single and Double Hearing Protection. Aviation, Space, and 

Environmental Medicine, 74, 937-946, September, 2003.

Mobley, Frank, McKinley, Richard, Yeager, TSgt. Donald, Measurement of AV-8B 

Cockpit Noise, JSF Program Office, 1213 Jefferson Davis Highway, Suite 600, Crystal 

Gateway 4, Arlington, VA, September 2003.

Atchley, A. A., Gabrielson ,T. B., McKinley, R. L., Preliminary Analysis of Nonlinearity 

in F/A-18E/F Radiated Noise, 16th Annual Office of Naval Research Propulsion 

Conference Proceedings, Los Angeles, California, June, 2003.

McKinley, Richard, Barrow, Charles, Davis, Capt Brian, D'Andrade, James, Mobley, 

Frank, and Janousek, James, Acoustical Noise Fields Generated on the Flightdeck During 

Operations of F/A-18C/D, F-14B, EA-6B, and S-3B Aircraft, JSF Program Office, 1213 

Jefferson Davis Highway, Suite 600, Crystal Gateway 4, Arlington, VA, September 

2002.

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McKinley, R., Communication and Localization with Hearing Protectors, NATO 

Research and Technology Organization, Human Factors and Medicine Panel, Lecture 

Series 219 on Damage Risk from Impulse Noise, St Petersburg, Russia; Bishkek, 

Kyrgyzstan May, 2002.

Barrow, C. W., McKinley, R.L., D’Andrade, J. A., Acoustical Noise Fields Generated On 

The Deck Of The USS Nassau During Shipboard Operations Of AV-8B Aircraft, JSF 

Program Office, 1213 Jefferson Davis Highway, Suite 600, Arlington, VA 22202, Jun 

2001

McKinley, R.L., Communication and localization with hearing protectors, North Atlantic 

Treaty Organization, Research and Technology Organization, Lecture Series 219, 

Damage Risk from Impulse Noise, RTO-EN-AC/323(HFM)TP/31, 4-1 – 4-14, Sep 2000.

Bolia, R. S. & McKinley, R. L., The effects of hearing protectors on auditory 

localization: evidence from audio-visual target acquisition, International Journal of 

Occupational Safety and Ergonomics, Vol 6, No. 3, 309-319, 2000.

Bolia, R. S., D’Angelo, W. R, & McKinley, R. L., Aurally Aided Visual Search in ThreeDimensional Space, Human Factors, Vol 41, No. 4, 664-669, Dec 1999.

Bolia, R. S., Ericson, M. A., Nelson, W. T., McKinley, R. L., & Simpson, B. D., A 

cocktail party effect in the median plane? Journal of the Acoustical Society of America

105:1390-1391, 1999.

Simpson, B. D., Bolia, R. S., Ericson, M. A., & McKinley, R. L., The effect of sentence 

onset asynchrony on call sign detection and message intelligibility in a simulated 

"cocktail party." Journal of the Acoustical Society of America 105:1024, 1999

McKinley, R. L., Ericson, M. A., Nelson, W. T., Bolia, R. S., & Simpson, B. D., A series 

of experiments exploring the spatial separation of multiple talkers using 3-D audio 

technology. Journal of the Acoustical Society of America 105:116, 1999

Nelson, W. T., Bolia, R. S., Ericson, M. A., and McKinley, R. L., Spatial audio displays 

for speech communications: a comparison of free field and virtual acoustic 

environments, Proceedings of the Human Factors and Ergonomics Society 43rd Annual 

Meeting, Houston, TX, Sep-Oct 1999.

McKinley, R., Loikith, G., and Downing, M., Acoustical noise fields generated during 

ground operations of F-14A aircraft, JSF Program Office, 1213 Jefferson Davis Highway, 

Suite 600, Arlington, VA 22202, Sep 1999.

McKinley, R., Loikith, G., and Downing, M., Acoustical noise fields generated during 

ground operations of F-18C aircraft, JSF Program Office, 1213 Jefferson Davis Highway, 

Suite 600, Arlington, VA 22202, Sep 1999.

McKinley, R., Loikith, G., and Downing, M., Acoustical noise fields generated during 

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August 2019 

ground operations of F-18E/F aircraft, JSF Program Office, 1213 Jefferson Davis 

Highway, Suite 600, Arlington, VA 22202, Sep 1999.

Loikith, G., McKinley, R., and Downing, M., Acoustical noise fields generated during 

ground operations of AV-8B aircraft, JSF Program Office, 1213 Jefferson Davis 

Highway, Suite 600, Arlington, VA 22202, Sep 1999.

Loikith, G., McKinley, R., and Downing, M., Acoustical noise fields generated during 

ground operations of EA-6B aircraft, JSF Program Office, 1213 Jefferson Davis 

Highway, Suite 600, Arlington, VA 22202, Sep 1999.

McKinley, R. L., & Bolia, R. S., The effects of hearing protectors on reaction times in 

audio-visual target acquisition. Proceedings of the 7th International Congress on Noise as 

a Public Health Problem, Sydney, Australia, pg 205-208, 1998.

Nelson, W. T., et al. , Effects of Localized Auditory Information on Visual Target 

Detection Performance Using a Helmet-Mounted Display, Human Factors, Vol. 40, No.3.

1998.

Nixon, C. W., et al. , Female Voice Communications in High level Aircraft Cockpit Noises 

– Part II: Vocoder and Automatic Speech Recognition systems, Aviation, Space, an d 

Environmental Medicine, Vol. 69, No. 11, 1998.

Nelson, W. T., Bolia, R. S., McKinley, R. L., Chelette, T. L., Tripp, L. D., & Esken, R., 

Localization of virtual auditory cues in a high +Gz environment. Proceedings of the 

Human Factors and Ergonomics Society 42nd Annual Meeting, 5-8 October 1998, 

Chicago, IL, pg 97-101.

Nelson, W. T., Bolia, R. S., Ericson, M. A., & McKinley, R. L., Monitoring the 

simultaneous presentation of multiple spatialized speech signals in the free field. 

Proceedings of the 16th International Congress on Acoustics and the 135th Meeting of the 

Acoustical Society of America, 2341-2342, 1998.

Nelson, W. T., Bolia, R. S., Ericson, M. A., & McKinley, R. L., Monitoring the 

simultaneous presentation of spatialized speech signals in a virtual environment. 

Proceedings of the 1998 IMAGE Conference, 159-166, 1998

McKinley, R. L., D’Angelo, W. R., Nelson, W. T., Perrott, D. R., & Bolia, R. S., Three 

experiments in aurally aided visual search. Journal of the Acoustical Society of America

102:3139, 1997.

McKinley, R. L., and Ericson, M. A., Flight Demonstration of a 3-D Auditory Display. 

Binaural and Spatial Hearing in Real and Virtual Environments, Lawrence Erlbaum and 

Associates, 683-700, 1996.

Ericson, M. A., and McKinley, R. L., The Intelligibility of Multiple Talkers Separated 

Spatially in Noise. Binaural and Spatial Hearing in Real and Virtual Environments, 

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Lawrence Erlbaum and Associates, 1996.

Perrott, D. R., Cisneros, J., McKinley R. L., & D’Angelo, W. R., Aurally aided visual 

search under virtual and free-field listening conditions. Human Factors, 38, 702-715, 

1996.

McKinley, R. L., et al., A Voice Communications Effectiveness Test (VCET), Audio 

Effectiveness in Aviation, AGARD Conference Proceedings 596, 7 Rue Ancelle, 92200 

Neuilly-Sur-Seine, France, 1996.

McKinley, R.L., Morris, Linda and Nixon, C. W., Special Applications of Active Noise 

Reduction Headsets, Audio Effectiveness in Aviation, AGARD Conference Proceedings 

596, 7 Rue Ancelle, 92200 Neuilly-Sur-Seine, France, 1996.

Nixon, C. W., et al., Vulnerability of Female Speech in Operational Noises, Audio 

Effectiveness in Aviation, AGARD Conference Proceedings 596, 7 Rue Ancelle, 92200 

Neuilly-Sur-Seine, France, 1996.

McKinley, R.L., D'Angelo, William R., Haas, Michael W., Perrot, David R., Nelson, W. 

Todd, Hettinger, Lawrence J., Brickman, Bart J., "An Initial Study of the Effects of 3-

Dimensional Auditory Cueing on Visual Target Detection," Proceedings of the Human 

Factors and Ergonomics Society 39th Annual Meeting, 119-123, October 1995.

Perrot, David R., Cisneros, McKinley, R. L., and D'Angelo, William R.,"Aurally Aided 

Detection and Identification of Visual Targets," Proceedings of the Human Factors and 

Ergonomics Society 39th Annual Meeting, 104-108, October 1995.

McKinley, R.L., D'Angelo, William R., Moore, Thomas J., "EW Applications of 3-D 

Auditory Displays," Proceedings of the Joint Electronic Warfare Conference, Pensacola, 

FL, May 1995.

McKinley, R.L., Ericson, M.A., and D'Angelo, W.R., "3-Dimensional Auditory Displays: 

Development, Applications, and Performance," Aviation, Space, and Environmental 

Medicine, May 1994.

McKinley, R.L. and Nixon, C.W., "Active Noise Reduction Headsets," Noise as a Public 

Health Problem, Michel Vallet, editor, Institut National de Recherche sur Les Transports 

et Leur Securite, Nice, France, 83-86, July 1993.

Ericson, M.A., McKinley, R.L., Kibbe, M. and Francis, D., "Laboratory and In-Flight 

Experiments to Evaluate 3-D Audio Display Technology," Proceedings SOAR 93, 

Houston TX, 1993.

Nixon, C.W., McKinley, R.L., Steuver, J.W. and McCavitt, A.R., "What Can Active 

Noise Reduction Headsets Do for You?" Proceedings of Hearing Conservation 

Conference 92, Cincinnati, OH, University of Kentucky, Engineering Continuing 

Education, April 1992.

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Ericson, M.A. and McKinley, R.L., "Human Auditory Localization Performance in 

Azimuth," AL-TR-91-0014, 1991.

Ericson, M.S. and McKinley, R.L., "Auditory Localization Cue Synthesis and Human 

Performance," NAECON 90 Proceedings, 718-754, May 1990.

Nixon, C.W., McKinley, R.L. and Steuver, J.W., "Performance of Active Noise 

Reduction Headsets," Basic and Applied Aspects of Noise-Induced Hearing Loss, 

Dancer, Salvi, Henderson, and Hammernik, editors, Mosby Yearbook, 1990.

Stephenson, M.R., Nixon, C.W., McKinley, R.L., Fisher V. and Jacobs, M., 

"Intelligibility of Digital Speech Masked by Noise: Normal Hearing and Hearing 

Impaired Listeners," AAMRL-TR-90-090, Jun 1990.

Ericson, M.A. and McKinley, R.L., "Auditory Localization Cue Synthesis and Human 

Performance," NAECON 89 Proceedings, Vol 2, 718-725, 1989.

McKinley, R.L. and Moore, T.J., "An Information Theory Based Model and Measure of 

Speech Communication Effectiveness in Jamming," Proceedings of Speech Tech '89, 

Media Dimensions, New York, 101-105, 1989.

McKinley, R.L. and Moore, T.J., "An Information Theory Based Model of Speech 

Communication Jamming," AAMRL-SR-88-052, 1988.

McKinley, R.L., "Concept and Design of an Auditory Localization Cue Synthesizer," 

AFIT Thesis, GE/ENG/88D-29, 1988.

Nixon, C.W. and McKinley, R.L., "Intelligibility in Noise of Three LPC Voice Channels 

with Active Noise Reduction Headsets," AAMRL-TR-88-063, 1988.

Nixon, C.W. and McKinley, R.L., "LPC-10 Intelligibility of Oxygen Masks and 

Microphones in Aircraft Noise," AAMRL-TR-88-048, 1988.

McKinley, R.L. and Moore, T.J., "Air Force Requirements for Speech Synthesis in 

Tactical Aircraft," Proceedings Speech Tech '87, Media Dimensions, New York, 152-

154, 1987.

Moore, T.J. and McKinley, R.L., "Laboratory Investigations of Voice Communications 

Jamming," Proceedings of AOC Western-Mountain Region Technical Symposium, San 

Antonio TX, 1987.

McKinley, R.L. and Moore, T.J., "Effect of Audio Bandwidth and Bit Error Rate on 

PCM, ADPCM, and LPC Speech Coding Algorithm Intelligibility," AGARD Conference

Proceedings, Information Management and Decision Making in Advanced Weapon 

Systems," 30.1-30.7, 1986.

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Nixon, C.W., McKinley, R.L. and Stock, M., "Design Guide for NORAD C3 Voice 

Communications Links," AAMRL-TR-86-018, March, 1986.

McKinley, R.L. and Moore, T.J., "Effects of Audio Bandwidth on Selected Digital 

Speech Coding Algorithms," Proceedings IEEE Military Communications Conference, 

Vol 1, 161-165, 1985.

Anderson, T.R., Moore, T.J. and McKinley, R.L., "Issues in the Development and Use of 

a Speech Recognition Data Base for Military Cockpit Environments," Proceedings of 

Speech Tech'85, Media Dimensions, NY, 172-176, 1985.

Moore, T.J., McKinley, R.L. and Nixon, C.W., "Laboratory Investigations of Voice 

Communications Jamming," AFAMRL-TR-81-110. Also in Proceedings of Second 

Annual Defense C3CM Conference, Bedford MA, 17-19 Nov 1981, and in Proceedings of 

the Air University's Sixth Airpower Symposium, 1982.

Anderson, T.R., McKinley, R.L. and Moore, T.J., "Evaluation of Speech Synthesis for 

Use in Military Noise," Proceedings of National Bureau of Standards Workshop on 

Standardization of Speech I/O Technology, 18-19, 241-245, 1982.

Nixon, C.W., McKinley, R.L. and Moore, T.J., "Effects of Training on Intelligibility of 

Jammed Voice Communications," Aviat. Space Environ. Med., 53, 239-244, 1982.

McKinley, R.L., Nixon, C.W., and Moore, T.J., "Voice Communication Capability of 

Selected In-flight Headgear Devices," AGARD Conference Proceedings No. 311, AURAL

COMMUNICATION IN AVIATION, 19.1-19.8, 1981.

Moore, T.J., Nixon, C.W. and McKinley, R.L., "Comparative Intelligibility of Speech 

Materials Processed by Standard Air Force Radio Systems in the Presence of Simulated 

Cockpit Noise," AGARD Conference Proceedings No.311, AURAL 

COMMUNICATION IN AVIATION, 14.1-14.5, 1981.

McKinley, R.L., "Voice Communications Research and Evaluation System," 

Proceedings IEEE, National Aerospace and Electronics Conference, NAECON 79, Vol 1, 

212, and AFAMRL TR-80-25, 1980.

McKinley, R.L., "Application of Commercially Available Filter Components for 

Psychoacoustic Testing," Proceedings IEEE 1978, National Aerospace and Electronics 

Conference, NAECON 78, Vol 1, 390-392, 1979.

Moore, T.J., McKinley, R.L., and Mortimer, V.D., "Comparative Intelligibility of 

Standardized Test Materials Processed by the ARC-164 and the ARC-34 Radio Systems 

in the Presence of Various Levels of Simulated Cockpit Noise," AMRL-TR-79-108, 

1979.

Moore, T.J., McKinley, R.L., Mortimer, V.D. and Nixon, C.W., "Evaluation of Word 

Intelligibility of Two Modems of a Spread Spectrum Communication System in Presence 

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of Simulated Cockpit Noise," AMRL-TR-78-54, 1978.

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RICHARD MCKINLEY

MATERIALS CONSIDERED

September 16, 2021

All materials referenced in my general report and publications on my curriculum vitae.

1. 3M (2012) 3M Combat Arms Technical Data Sheet. 3M Technical Datasheet 2012

2. 3M (2015) Lab Attenuation Data for 3M HPDs. 3M (2015)

3. 3M (2015) Technical Data Bulletin 234 Hearing Protection for Impulse Noise. 3M (2015)

4. Abel (2003) Acoustical Performance of the Communications Ear Plug (CEP) in combination with 

the Gentex SPH-5 flight helmet. Technical Report TR 2003-077. Toronto, Ontario, Canada, 

DRDC-Toronto.

5. Abel (2004) Sound Attenuation of the Indoor-Outdoor Range E-A-R Plug. Military medicine 

2004; 7(169): 551-555.

6. Abel (2005) Hearing loss in military aviation and other trades: investigation of prevalence and 

risk factors. Aviation, space, and environmental medicine 2005; 12 (76): 1128-1135.

7. Abel (1986) Noise-Induced Hearing Loss and Hearing Protective Devices. Can J of Public Health 

1986; 77(1): 104-107

8. Abel (2004) Sound Attenuation of the Indoor-Outdoor Range EAR Plug. Military Medicine 2004; 

7 (169): 551-555

9. Abel (2008) An Investigation of the attenuation provided by the Surefire EP3 Sonic Defender 

Earplug (comparison to CAEv2). DRDC Toronto TR 2008-040

10. Abel (2010) Laboratory Performance of the Single-Sided E-A-R Combat Arms Hearing 

Protective Earplug. Can Accoust 2010; (38) 2

11. Abrams (2013) Using Hearing Aid Signal Processing for Hearing Protection. Innovations 2013; 3 

(3):42-45

12. Abrams, H. et al (2002) A cost-utility analysis of adult group audiologic rehabilitation - Are the 

benefits worth the cost? J Rehabil Res Dev. 2002 Sep-Oct;39(5):549-58

13. Abrams, T., et al (2006) The Relationship Between Hearing Impairment and Depression in Older 

Veterans. J Am Geriatr Soc. 2006 Sep;54(9):1475-7

14. Abstract (2017) Noise-Induced cochlear synaptopathy in rhesus monkeys (Macaca mulatta). Hear 

Res. 2017 Sep; 353:213-223

15. Adams (2020) Tinnitus Neuroimaging. Otolaryngol Clin North Am. 2020 Aug;53(4):583-603

16. adults, International Journal of Audiology, 49:8, 580-585

17. Aedo & Aguillar (2020) Cochlear synaptopathy - new findings in animal and human research. 

Rev Neurosci. 2020 Aug 27;31(6):605-615

18. AFI 48-20 Occupational Noise and Hearing Conservation Program, revised to AFI 48-127 

(2016);

19. Ahroon, W., et al (2011) Analysis of army-wide hearing conversation database for hearing 

profiles related to crew-served and individual weapon systems. Noise Health. 2011 JanFeb;13(50):76-83

20. Ahuja (2005) Noise reduction through circulation control. 39th Aerospace Sciences Meeting and 

Exhibit 2001 (p. 666).

21. AIBS (2010) Peer Review of Injury Prevention and Reduction Research Task Area Impulse 

Noise Injury Models

22. Akil (2006) Progressive Deafness and Altered Cochlear Innervation in Knock-Out Mice Lacking 

Prosaposin. J Neurosci. 2006 Dec 13;26(50):13076-88

23. Akil (2008) Localization of Synucleins in the Mammalian Cochlea. J Assoc Res Otolaryngol. 

2008 Dec;9(4):452-63

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24. Akil (2015) Spiral Ganglion Degeneration and Hearing Loss as a Consequence of Satellite Cell 

Death. J Neurosci. 2015 Feb 18; 35(7):3263-75

25. Akil (2018) Virally Mediated Overexpression of Glial-Derived Neurotrophic Factor. Hum Gene 

Ther. 2019 Jan;30(1):88-105

26. Al-Omari, A., et al (2018) Association of Flying Time with Hearing Loss in Military Pilots. Saudi 

J Med Med Sci. 2018 Sep-Dec; 6(3):155-159

27. Alali (2010) The Challenge of Localizing Vehicle Backup Alarms: Effects of passive and 

electronic hearing protectors, ambient noise level, and backup alarm spectral content. Noise 

Health. 2011 Mar-Apr; 13(51):99-112

28. Alamgir (2016) Economic Burden of Hearing Loss for the US Military: A Proposed Framework 

for Estimation. Mil Med. 2016 Apr; 181(4):301-6

29. Alamgir (2016) The Impact of Hearing Impairment and noise-induced hearing injury on quality 

of life in the active-duty military population: challenges to the study of this issue. Mil Med Res. 

2016 Apr 12;3:11

30. Alamgir (2016) Economic Burden of Hearing Loss for the US Military. Mil Med. 2016 

Apr;181(4):301-6

31. Alberti (2001) The Anatomy and Physiology of the Ear and Hearing. Occupational exposure to 

noise: Evaluation, prevention, and control (2001): 53-62

32. Alberti (1995) NIOSH.pdf

33. Aldag (2017) The Biological Basis of Chronic Traumatic Encephalopathy following blast injury: 

A literature review. J Neurotrauma. 2017 Sep;34(S1): S26-S43

34. Allen and Berger (1990) Development of Passive Hearing Protector with Level Dep. Flat Atten. 

Characteristics. Noise Control Engineer. J.1990; 3 (34): 97-104

35. Altschuler (2019) Small Arms Fire-Like Noise - Effects on Hearing Loss. Neuroscience 2019 

May 21; 407:32-40

36. Alvarado (2020) Antioxidants and Vasodilators for the Treatment of Noise-Induced Hearing 

Loss. Front Cell Neurosci. 2020 Jul 22; 14:226

37. Alvord (1997) Anatomy and orientation of the human external ear. J Am Acad Audiol 1997; 8: 

383-390

38. Alvord (1997) Anatomy of an earmold-a formal terminology. J AM Acad Audiol 1997; 8: 100-

103

39. Amant (2020) Abstract Genetic Inheritance and Its Contribution to Tinnitus. Curr Top Behav 

Neurosci. 2020 (Jul 24)

40. American Academy of Audiology (2003) Position Statement Preventing Noise-Induced 

Occupational Hearing Loss. LOSS, PREVENTING NOISE-INDUCED OCCUPATIONAL 

HEARING. "Position Statement." (2003).

41. American Institute of Biological Sciences (2010). Peer Review of Injury Prevention and 

Reduction Research Task Area Injury Models

42. Amrein (2012) High Level Impulse Sounds and Human Hearing: Stamdards, Physiology, 

Quantification. ARL-TR-6017; 2012 May

43. Amrein (2012) High Level Impulse Sounds and Human Hearing Standards, Physiology, 

Quantification.pdf. (2012) Army Research Laboratory

44. ANSI (2016) Methods for measuring the real-ear attenuation of hearing protectors. ANSI/ASA. 

2016; S12.6

45. ANSI (2008) Methods for measuring the real-ear attenuation of hearing protectors. ANSI/ASA. 

2008; S12.6

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 128 of 171
46. ARL PPT - Sound Localization with the Combat Arms Earplug. DOD Touhy Production 

Document

47. Army (2019) FOIA Response Criminal Investigation Command. Dept. of the Army 2019 Mar.

48. Associated Press (2005). Soldiers in Iraq praise quick, quiet Stryker. Ass. Press 2005 Apr. 

6https://tdn.com/news/soldiers-in-iraq-praise-quick-quiet-stryker/article.

49. ATA (2009) 2009 PDR GUIDE TO DRUG INTERACTIONS, SIDE EFFECTS AND 

INDICATIONS FOR TINNITUS.pdf

50. Attias (2002) Support for the central theory of tinnitus generation: a military epidemiological 

study. International journal of audiology 2002, (41): 301-307.

51. Audiologic characteristics in a sample of recently-separated military Veterans: The Noise 

Outcomes in Service Members Epidemiology Study. (2017) Hearing Research 349 21-30

52. Aulet (2014) A Case of Heroin Induced Sensorineural Hearing Loss.pdf. (2014) Case Reports in 

Otolaryngology, Volume 2014, Article ID 962759, 1-4

53. Azam (2010) Noise induced hearing loss: profile in military service. PAFMJ 2010 Dec 31

54. Babeu (2005) Level Dependent Hearing Protection and DPOAE After Small Arms Fire

55. Baguley (2013) Tinnitus. Seminar 2013; (382): 1600-1607

56. Baiduc, R., et al (2013) Clinical Measures of Auditory Function - The Cochlea and Beyond. Dis 

Mon. 2013 Apr;59(4):147-56

57. Bakay (2018) Hidden hearing loss selectively impairs neural adaptation to loud sound 

environments. Nat Commun. 2018 Oct 16;9(1):4298

58. Bao (2013) Prophylactic and therapeutic functions of drug combinations against noise-induced 

hearing loss.pdf. (2013) Hearing Research 304, 33-40

59. Barbee (2018) Effectiveness of Auditory Measures for Detecting Hidden Hearing Loss and.or 

Cochlear Synaptopathy. Semin Hear. 2018 May;39(2):172-209

60. Barberi (2019) Ototoxic Adverse Drug Reactions A Disproportionality Analysis Using the Italian 

Spontaneous Reporting Database.pdf. (2019) Frontiers in Cellular Neuroscience Ototoxic 

Adverse Drug

61. Bartels (2008) The Additive Effect of Co-occurring Anxiety and Depression on Health Status, 

Quality of Life and Coping Strategies in Help-Seeking Tinnitus Patients. Ear Hear. 2008 

Dec;29(6):947-56

62. Berger (1994) Development of a new standard laboratory protocol for estimating the field 

attenuation of hearing protection devices. Part III The validity of using subject-fit data. The 

Journal of the Acoustical Society of America 1998; 2 (103): 665-672.

63. Berger (1994) Development of a new standard laboratory protocol for estimating the field 

attenuation of hearing protection devices.PartIII.The validity of using subject-fit data. The Journal 

of the Acoustical Society of AmericaÊ1998; 2 (103): 665-672.

64. Berger (1994) In Search of Meaningful Measures of Hearing Protector Effectiveness. Spectrum 

Suppl,Ê1996; (13): 2913, 29.

65. Berger (1994) International Review of Field Studies of Hearing Protector Attenuation. Scientific 

basis of noise-induced hearing lossÊ(1996): 361-377.

66. Berger (2001) Bibliography on Hearing Protection, Hearing Conservation, and Aural Care, 

Hygiene and Physiology. E-A-R 82-6/HP 2001

67. Berger (2003) Does Loud Music During Exercise Affect Hearing?. Journal of Scientific 

Exploration 2003; 4Ê(17): 687-703.

68. Berger (2005) Comparing hearing protector ratings - NRR, SNR, SLC, and others

69. Berger (2005) Options in Defining Background Noise During Audiometric Testing. CAOHC 

UpdateÊ2005; 1 (18)

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70. Berger (2005) Overview and Index to the EARlog Series Numbers 1-21. EARLog 2005 Series 

Numbers 1-21

71. Berger (2005) Preferred Methods for Measuring Hearing Protector Attenuation. INTER-NOISE 

and NOISE-CON Congress and Conference Proceedings 2005; 3 (2005): 4432-4441 Institute of 

Noise Control Engineering

72. Berger & Hamery (2008) Empirical Evaluation of Impulse Noise of the Level Dependency of 

Various Passive Earplugs. J. Acoust. Soc. Am. 2008; 5 (123): 3528

73. Berger (1979) The Effects of Hearing Protectors on Auditory Communications. Cabor 

Corporation, EAR Division 1983

74. Berger (1980) Hearing Protector Performance: How They Work-and-What Goes Wrong in the 

Real World. Journal of Sound and Vibration 1980; 10 (14): 14-17

75. Berger (1980) The Performance of Hearing Protectors in Industrial Noise Environments. 

EARLOG-Aearo Company-Lit Code 30295 1980

76. Berger (1981) Details of Real World Hearing Protector Performance as Measured in the 

Laboratory. INTER-NOISE and NOISE-CON Congress and Conference Proceedings 1981; 1 

(1981): 147-152

77. Berger (1981) Extra-Auditory Benefits of a Hearing Conservation Program. EARLOG-Aearo 

Company 1980

78. Berger (1981) Motivating Employees to Wear Hearing Protection Devices. Occupational Health 

& Safety 1987; 3 (56): 57-58

79. Berger (1982) Responses to Questions and Complaints Part I. Cabot Corporation, EAR Division, 

1983.

80. Berger (1982) Responses to Questions and Complaints Part II. Cabot Corporation, EAR Division, 

1983.

81. Berger (1983) Considerations Regarding the Laboratory Measurement of Hearing Protector 

Attenuation. INTER-NOISE and NOISE-CON Congress and Conference Proceedings 1983; 4 

(1983): 379-382

82. Berger (1983) Responses to Questions and Complaints Part III. Cabot Corporation, EAR

Division, 1983.

83. Berger (1983) The Hearing Conservation Amendment Part I. Cabot Corporation, EAR Division, 

1983.

84. Berger (1984) Attenuation of Earplugs Worn in Combination with Earmuffs. Occupational Health 

and Safety (Waco, Tex.) 1984: 72

85. Berger (1984) Protection for Infrasonic and Ultrasonic Noise Exposure. J. Occup. Med 1984; 9 

(26): 649-656

86. Berger (1984) The Hearing Conservation Amendment Part II. Cabot Corporation, EAR Division, 

1984.

87. Berger (1986) Noise & Hearing Conservation Manual Fourth Edition. Amer Indus. Hyg. Assn 

1986

88. Berger (1988) Tips for Fitting Hearing Protectors. Sound and Vibration 1988; (6): 22-25

89. Berger (1993) Establishing the 'True' Laboratory. 18th Annual Conference of the National 

Hearing Conservation Association, Albuqurque, NM, Spectrum Vol. 10, Suppl. 1, p. 19 (1993).

90. Berger (1994) History and Development of the EAR Foam Earplug. The Journal of the 

Acoustical Society of AmericaÊ1994; 5 (95): 2914-2914.

91. Berger (1998) Development of a new standard laboratory protocol. J Acoust Soc Am. 1998 

Feb;103(2):665-72

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 130 of 171
92. Berger (2000) Musical Acoustics: Concert Performance by the American Brass Band. FRENCH 

GERMAN RESEARCH INST CEDEX (FRANCE), 2000.

93. Berger (2000) The Naked Truth about NRRs. Cabot Safety 1993

94. Berger (2003) Hearing Protection Devices. The Noise Manual-American Industrial Hygiene 

Assoc. 2003; 5th Edition

95. Berger (2003) Hearing protection Surpassing the limits to attenuation imposed by the bone 

conduction pathways.pdf. (2003) Acoustical Society of America-Vol. 114, No. 4, Pt. 1

96. Berger (2003) Noise Manual 5th edition. Berger, E. H. (Ed.). (2003).ÊThe noise manual. Aiha.

97. Berger (2004) Keeping Noise at Bay. Safety + Health 2004; 5 (169): 52

98. Berger (2005) Noise Nav 1.8.pdf. (2005) Noise Navigator Sound Level Database

99. Berger (2007) Hearing Protection Devices. Encyclopedia of Accoustics, Chapter 81: 967-981

100. Berger (2007) Methods of Developing and Validating a Field -MIRE Approach for Measuring 

Hearing Protector Attenuation. Spectrum 2007 Feb; (24) Suppl 1.

101. Berger (2007) The Noise Stops Here - Experimental HPD Fitting Workshop. 33rd Annual 

Conference of the National Hearing Conservation Association, Portland, OR, Spectrum Vol. 25, 

Suppl. 1 (2007)

102. Berger (2008) Methods of Fit Testing Hearing Protectors, with representative field test data. 

Hearing Loss (ICBEN) 2008

103. Berger (2008) Why Can't I Measure Sound Exposures from MP3 Players (iPod or equivalent) or 

from a Peltor Worktunes, style earmuff,with a simple microphone?. E-A-RCAL Laboratory 2008 

Feb

104. Berger (2010) Empirical Evaluaion using Implulse Noise of the level-dependency of various 

passive earplug designs. J. Acoust. Soc. Am. 2008 June;

105. Berger (2010) Hearing through the Protectors. IHN 2010 July/August

106. Berger (2010) What is a Personal Attenuation Rating (PAR)?. E-A-RCAL 07-21/HP; 2010 April

107. Berger (2011) Custom Hearing Protection Have It Your WayÉMaybe. IHN 2011 May/June

108. Berger (2011) Development and Validation of a field microphone-in-real-ear approach for 

measuring hearing protector attenuation. Noise Health. 2011 Mar-Apr;13(51):163-75

109. Berger (2014) Evaluation of Variability in real-ear attenuation testing using a unique 

databaseÑ35 years of data from a single laboratory. The Journal of the Acoustical Society of 

America 2014; 4 (136): 2134

110. Berger (2016) 6th Edition of The Noise Manual (3M Employee) Hearing Protection Devices. In 

The Noise Manual, 6th Ed.; Chapt. 11, Am Ind Hygn Assoc. 2017

111. Berger (2016) Review of the 2016 Edition of ANSI S12.6 and its place in the panoply of 

standards on the measurement of real-ear attenuation at threshopld since 1957. J Acoust Soc Am. 

2018 Oct;(140)4

112. Berger (xxxx) EARLog 13 Attenuation of Earplugs Worn in Combination with Earmuffs.pdf. 

(xxxx) EAR Log 13

113. Berger and Hamery (2008 ) Impulse Noise Evaluation of Level-Dependency in Various Passive 

Earplugs (V4.0). J. Acoust. Soc. Am. 2008; 5 (123): 3528

114. Berger EH. (2005) Preferred methods for measuring hearing protector attenuation. In: 

Proceedings of internoise 2005, Rio de Janeiro, Brazil; p. 58.

115. Berger(2003) Noise Control and Hearing Conservation: Why Do It?. The noise manual. Fairfax, 

VA: American Industrial Hygiene Association.

116. Berger, E. (2011) Custom Hearing Protection Have It Your Way.. Maybe. Industrial Hygiene 

News. May/June 2011 Issue.

117. Berger, E., (2014) 3M E-A-Rfit Validation System Frequently Asked Questions (April).

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 131 of 171
118. Berger, et al. (1998) Development of a New Standard Laboratory Protocol for Estimating HPD 

Field Attenuation. ÊThe Journal of the Acoustical Society of America 1996; 3 (99): 1506-1526.

119. Berger, Royster (1996) In Search of Meaningful Measures of Hearing Protector Effectiveness. 

Spectrum Suppl 1996; 1 (13): 29

120. Berlin (xxxx) The Programmed Instruction in the Decibel.pdf

121. Bezandry (2016) Effects of Hearing Protection Device Attenuation on Unmanned Aerial Vehicle 

Audio Signatures. ARL-TR-7639 2016 Mar

122. Bharadwaj (2019) Non-Invasive Assays of Cochlear Synaptopathy - Candidates and 

Considerations. Neuroscience 2019 May 21;407:53-66

123. Bhatt (2016) Analysis of audiometric notch as a noise-induced hearing loss phenotype in US 

youth data from the National Health And Nutrition Examination.pdf. (2017) International Journal 

of Audiology; Early Online: 1Ð8

124. Bhatt (2020) Association Analysis of Candidate Gene Polymorphism and Audiometric Measures 

of NIHL. Otol Neurotol. 2020 Jun;41(5):e538-e547

125. Bielefeld (2015) Protection from noise-induced hearing loss with Src Inhibitors. Drug Discov 

Today. 2015; 6 (20):760-765

126. Bielefeld (2019) Pharmaceutical Otoprotection Strategies to Prevent Impulse Noise-Induced 

Hearing Loss. J Acoust Soc Am. 2019 Nov;146(5):3790

127. Bilgili (2017) Continuing Education - Drug-Induced Ototoxicity.pdf

128. Bjorn (2005) US Navy Flight Deck Hearing Protection Use Trends: Survey Results. NAVAL 

AIR WARFARE CENTER AIRCRAFT DIV PATUXENT RIVER MD. 2006

129. Blackwell, DL., et al (2014) Summary Health Statistics for U.S. Adults - National Health 

Interview Survey, 2012. Vital Health Stat 10. 2014 Feb;(260):1-161

130. Blair, M. (2020) Retrospective Cohort Study of Pure tone Audiometry Threshold Shifts from 

Ototoxic Substance, Continuous Noise, and Impulse Noise Exposures at Tinker Air Force Base 

from 2005 to 2019. Air Force Institute of Technology. Theses and Diss. 2020 (3226)

131. Blioskas (2018) Utility of Otoacoustic Emissions and Olivocochlear Reflex in Predicting 

Vulnerability to Noise-Induced Inner Ear Damage. Noise Health. 2018 May-Jun;20(94):101-111

132. Boettcher (1987) Synergistic Interactions of Noise and Other Ototraumatic Agents.pdf. (1987) 

Ear and Hearing; Volume 8, No 4, 192-212

133. Binseel (2012) A Comparison of the Single-Sided and Double Sided Combat Arms Earplugs. 

ARL-TR-6270 2012: 1-42

134. Bohnker (2002) U.S. Navy and Marine Corps Hearing Conservation Program 1995-1999: Mean 

Hearing Threshols for Enlisted Personnel by Gender and Age Groups. Military MedicineÊ2020; 2 

(167): 132-135.

135. Bohnker (2002) Navy Hearing Conservation Program - Threshold Shifts in Enlisted Personnel, 

1995-1999. Military medicine 2002; 1 (167): 48-52

136. Borghi (2005) Prevalence of Tinnitus in Patients with Hypertension and the Impact of Different 

Antihypertensive Drugs on the Incidence of.pdf. (2005) Current Theraputic Research VOLUME 

66, NUMBER 5

137. Bowes (2006) Computing the Return on Noise Reduction Investments in Navy.pdf. (2006) CAN

138. Bramhall (2018) Use of Non-Invasive Measures to Predict Cochlear Synapse Counts. Hear Res. 

2018 Dec;370:113-119

139. Bramhall (2019) Characterizing noise-induced hidden hearing loss in veterans. J. Acoust. Soc. 

Am. 2019 Mar; 3(145) Pt. 2:1907

140. Bramhall (2019) The Search for Noise-Induced Cochlear Synaptopathy in Humans. Hear Res. 

2019 Jun;377:88-103

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 132 of 171
141. Bramhall (2019) Tinnitus and Auditory Perception After a History of Noise Exposure 

Relationship to Auditory Brainstem Response Measures.pdf. (2019) EAR & HEARING, VOL. 

39, NO. 5, 881Ð894

142. Bramhall, N., et al (2019) The search for noise-induced cochlear synaptopathy in 

humans:Mission impossible. Hear Res. 2019 Jun; 377:88-103

143. Breitzler (2020) Noise-Induced Hearing Loss in Zebrafish. Hear Res. 2020 Jun;391:107952

144. Bressler (2017) Sensory coding and cognitive processing of sound in Veterans with blast 

exposure. Hear Res. 2017 Jun;349:98-110

145. Brown (2015) Effects of Active and Passive Hearing Protection Devices on Sound Source 

Localization, Speech Recognition, and Tone Detection. PLoS ONE 2015; 8 (10): 1-21

146. Brueck (2013) Measurement Exposure Impulsive Noise at Indoor and Outdoor Firing Ranges 

during Tactical Training Exercises. HHS - CDC - NIOSH 2014;

147. Brungart (2007) A Comparison of Acoustic and Psychoacoustic Measurements of Pass-Through 

Hearing Devices. IEEE Workshop on Applcation of Signal Processing to Audio and Accoustics; 

October 21-24, 2007, New Paliz, NY

148. Brungart (2017) Development and validation of the Speech Reception in Noise (SPRINT) Test. 

Hear Res. 2017 Jun;349:90-97

149. Buck (2000) Performace of Hearing Protectors in Impulse Noise

150. Buck (2000) Performance of Hearing Protectors in Impulse Noise (Defense Technical Notice 

ADP010342). (Defense Technical Notice ADP010342)-French German Research Inst CEDEX 

(France) 2000: 3-1-3-10

151. Buck (2010) The European Regulation 2003-10-EC and the Impact of its Application to the 

Military Noise Exposure. ICA 2010 Aug 23-27

152. Byrne (2011) Relationship between comfort and attenuation measurements for two types of 

earplugs. Noise Health. 2011 Mar-Apr;13(51):86-92

153. Byrne (2017) Inter-laboratory Comparison of Three Earplug Fit-test Systems. J Occup Environ 

Hyg. 2017 Apr;14(4):294-305

154. Byrne (2017) Inter-Laboratory Comparison of Three Earplug Fit-Test Systems. Journal of 

Occupational and Environmental Hygiene 2017; 4 (14): 294-305

155. Byun (2020) Transcutaneous Electrical Nerve Stimulation for Treatment of Tinnitus A 

Systematic Review and Meta-analysis. Otol Neurotol. 2020 Aug;41(7):e767-e775

156. Cacace (2002) Expanding the biological basis of tinnitus - crossmodal origins and neuroplasticity. 

Hear Res. 2003 Jan;175(1-2):112-32

157. CAE Filter Technial Drawings 4047. 3M_MDL000481954-3M_MDL000481954

158. CAEv4.1 Sell Sheet with Comments. 3M_MDL000259866-3M_MDL000259918

159. Campbell (2011) Detection of Ototoxicity.pdf. (2011) SEMINARS IN HEARING/VOLUME 32, 

NUMBER 2, 196-202

160. Campbell, et al (2016) Guidelines for Auditory Threshold Measurement for Significant Threshold 

Shift. Otol Neurotol. 2016 Sep;37(8):e263-70

161. Canetto (2008) Hearing Protectors Real World Performance and the European Directive 2003 10 

EC. JOSE 2009; (15) 2:221-226

162. Cantley (2019) Early Hearing Slope as a Predictor of Subsequent Hearing Trajectory. J Acoust 

Soc Am. 2019 Nov;146(5):4044

163. CAOHC Hearing Conservation Manual (Fifth Edition). Council for Accreditation in 

Occupational Hearing Conservation 2014

164. Carney (2018) Supra-threshold Hearing and Fluctuation Profiles: Imlications for sensorineural 

and hidden hearing loss. J Assoc Res Otolaryngol. 2018 Aug;19(4):331-352

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 133 of 171
165. Carroll, Y., et al (2017) Vital Signs - Noise-Induced Hearing Loss Among Adults - US 2011-

2012. MMWR Morb Mortal Wkly Rep. 2017 Feb 10;66(5):139-144

166. Casali (1990) Attenuation Performance of Four Hearing Protectors under Dynamic Movement 

and Different User Fitting Conditions. Human Factors 1990; 1 (32): 9-25

167. Casali (2009) A field investigation of hearing protection and hearing enhancement in one device: 

For soldiers whose ears and lives depend upon it. Noise and Health 2009; 11(42): 69

168. Casali (2010) In-Field Localizaiton of Gunshots in Azimuth under Two Prototype Etymotic and 

Two Production AEARO-Peltor Hearing Protection/Enhancement Devices Intended for Military 

Ground Soldier Applications. ETYMOTIC Gunshot Localization Experiment; 2010 June

169. Casali (2011) Warfighter Auditory Situation Awareness: Locating the Shooter with and without 

Hearing protection. Naval Engineers Journal 2012; (124.1): 149-159

170. Casali (2013) Implications if Your Life Depends upon Your Hearing: The NRR vs. the ASAF. 

National Hearing Conservation Association, St. Petersburg, FL (2013)

171. Casali (2015) Objective Metric-Based Assessments for Efficient Evaluation of Auditory Situation 

Awareness. Auditory Systems Lab 2015;

172. Casali xxxx DRILCOM Final Report. DRILCOM:2-95

173. Casali, (2009) A Field Investigation of Hearing Protection and hearing enhancement in one 

device: For soldiers whose ears and lives depend on it. Noise Health. 2009 Jan-Mar;11(42):69-90

174. Casali, Berger (1996) Technology Advancements in Hearing Protection Circa 1995 (add to S 

Drive). Amer Industrial Hygiene Assoc. J. 1996; 2 (57): 175-185

175. Casali, J., Berger, E. Technology Advancements in Hearing Protection Circa 1995. (1996). 

Active Noise Reduction, Frequency Amplitude-Sensitivity, and Uniform Attenuation. AIHA 

Journal

176. Cason (2012) Air Force Hearing Conservation Program Data 1998-2008: A cross-sectional 

analysis of positive threshold shifts. Mil Med. 2012 May;177(5):589-93

177. Caspary, D. & Llano, D. (2017) Auditory thalamic circuits and GABA receptor function -

Putative mechanisms in tinnitus pathology. Hear Res. 2017 Jun; 349:197-207

178. Cavallaro (2009) Army Says New Earplugs Will Save Soldiers Hearing. Army Times; 2009 Oct

179. Cave (2010) Evolution of the Army Hearing Program in a Deployed Environment. US Army Med 

Dep J. 2010 Apr-Jun:65-7

180. Cave, K., et al (2007) Blast Injuiry of the Ear - Clinical Update from the Global War on Terror. 

Mil Med. 2007 Jul;172(7):726-30

181. Chan (2016) Impulse Noise Injury Model. Mil Med. 2016 May;181(5 Suppl):59-69

182. Chen (2020) Ginsenoside Rd Amliorates Auditory Cortex Injury. Front Physiol. 2020 Jul 21;

11:788

183. Chen (2020) Novel Oral Multifunctional Antioxidant Prevents Noise-Induced Hearing Loss and 

Hair Cell Loss. Hear Res. 2020 Mar 15; 388:107880

184. Chen, H., et al (2019) Noise-induced Cochlear Synaptopathy and Signal Processing Disorders. 

Neuroscience. 2019 May; 407:41-52

185. Chen, Y, et al (2017) Tinnitus and hyperacusis - Contributions of paraflocculus, reticular 

formatoin and stress. Hear Res. 2017 Jun;349:208-222

186. Cho, S., et al (2013) Mechanisms of Hearing Loss after Blast Injury to the Ear. PLoS One. 2013 

Jul; 8(7):e67618

187. Cianfrone (2011) Pharmacological drugs inducing ototoxicity, vestibular symptoms and tinnitus: 

a reasoned and updated guide. Eur Rev Med Pharmacol Sci. 2011 Jun;15(6):601-36

188. Clavler (2012) Measurement of Bone-Conducted Impulse Noise from Weapons Using a Head 

Simulator. J. Acoust. Soc. Am. 2012; (132) 3:2014

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 134 of 171
189. Cleveland (2009) Fort Carson: An Army Hearing Program Success Story. US Army Med Dep J. 

2009 Apr-Jun:67-75

190. Clifford (2019) Untangling the Genomics of Noise-Induced Hearing Loss and Tinnitus. J Acoust 

Soc Am. 2019 Nov;146(5):4007

191. Clifford, R., et al (2016) The Genomic Basis of Noise-induced Hearing Loss - A Literature 

Review Organized by Cellular Pathways. Otol Neurotol. 2016 Sep; 37(8):309-16

192. Clifford, R., et al (2019) Impact of TBI, PTSD, and Hearing Loss on Tinnitus Program in a US 

Marine Cohort. Mil Med. 2019 Dec 1;184(11-12):839-846

193. Coelho (2020) Classification of Tinnitus - Mutiple Cuases with the Same Name. Otolaryngol Clin 

North Am. 2020 Aug;53(4):515-529

194. Cohen, J., et al (2002) Blast Injury of the Ear in a Confined Space Explosion - Auditory and 

Vestibular Evaluation. Isr Med Assoc J. 2002 Jul;4(7):559-62

195. Comprehensive Hearing Health Patient Brochure

196. Congressional Record. Arms Sales Notification 

197. Cooper (2014) The Department of Defense Epidemiologic and Economic Burden of Hearing Loss 

Study. Mil Med. 2014; 12 (179): 1458-1464

198. Couth (2020) Investigating the Effects of Noise Exposure on Self-Report, Behavioral and 

Electrophysiological Indices. Hear Res. 2020 Sep 15; 395: 108021

199. Cox, H.J. & Ford, G.R. (1995) Hearing loss associated with weapons noise exposure - when t 

investigate an asymetrical loss. J Laryngol Otol. 1995 Apr;109(4):291-5

200. Cruickshanks, K., et al (2010) Education, Occupation, Noise Exposure History and the 10-yr 

Cumulative Incidence of Hearing Impairment in Older Adults. Hear Res. 2010 Jun 1;264(1-2):3-9

201. Curhan (2012) Prospective Study of Alcohol Use and Hearing Loss in Men.pdf. (2011) Ear Hear, 

32(1)

202. CVC Combat Vehicle Crewman Helmet System featuring Bose. Gentex. 2017

www.gentexcorp.com

203. CVC M9 Operation and Maintenance Manual. Gentex. 2017 www.gentexcorp.com/patents

204. MCO 6260.3 Series - Marine Corps Hearing Conservation Program

205. OPNAVINST 5100.19 Series - Hearing Conservation (Afloat)

206. OPNAVINST 5100.23 Series - Hearing Conservation (Shore)

207. Dancer (1994) A New Nonlinear Earplug for Use in High Level Impulse Noise Environment. The 

Journal of the Acoustical Society of AmericaÊ1998; 5 (1103): 2878-2878.

208. Dancer (1997) Study and production of nonlinear perforated earplugs. Saint-Louis FrancoGerman Research Institute-Tr. Ed. 1994 Report, R 128/97

209. Dancer (2005) NoiseÑA Limiting Factor for the Use of Modern Weapon Systems?. NSTITUT 

FRANCO-ALLEMAND DE RECHERCHES SAINT-LOUIS (FRANCE) 2005.

210. Dancer (1995) Hearing Hazard from Impulse Noise: a Comparative study of Two Classical 

Criteria for Weapon Noises (Pfander Criterion and Smorrenburg Criterion) and the LAeq8 

Method. Acta Acustica 1995; 3: 539-547

211. Dancer (1999) Hearing Protection in the Military Environment. Noise & Health 1999; 5: 1-15

212. Dancer et al (1992). J. Acoustical Soc. America 91(3), 1677-1689

213. Daniel L. Johnson Army Research Lab Blast Overpressure Studies (1st Rog Response). USAARL 

Contract Report N. CR-98-03 1998

214. Davis (2017) Impulsive Noise A Brief Review. Hearing Research 2017; (349): 34-36

215. Davis (2019) In-Ear and On-Body Measurements of Impulse Noise Exposure. Int J Audiol. 2019 

Feb; 58(sup1):S49-S57

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 135 of 171
216. Davis (2019) In-ear and On-body Measurements of Impulse-noise Exposure. Intl. J. of Audiology 

2019; S1 (58): S49-S57

217. Davis, R. & Claiver, O. (2017) Impulsive noise - A brief review. Hear Res. 2017 Jun;349:34-36

218. Davis, R. (2017) Long-term noise exposures - A brief review. Hear Res. 2017 Jun;349:31-33

219. Dawes (2019) Relationship Between Diet, Tinnitus, and Hearing Difficulties.pdf. (2020) Ear & 

Hearing; 41; 289Ð299

220. De Paolis (2017) Analytical and numerical modeling of the hearing system - Advances towards 

the assessment of hearing damage. Hear Res. 2017 Jun;349:111-128

221. De Paolis (2017) Human Cochlear Hydrodynamics: A high-resolution CT-Based finite element 

study. J Biomech. 2017 Jan 4;50:209-216

222. De Ru, A., et al (2014) Voluntary contraction of the tensor typani muscle and its audiometric 

effects. J Laryngol Otol. 2014 Mar 19:1

223. Deiters (2019) Generalizability of Clinicaly Measured Acoustic Reflexes. J Acoust Soc Am. 2019 

Nov; 146(5):3993

224. Deiters (2019) Generalizability of clinically measured acoustic reflexes to brief sounds. The 

Journal of the Acoustical Society of Amer. 2019; 5 (146): 3993-4006

225. Deklerk (2020) Identifying non-otologic risk factors for tinnitus - a systematic review. Clin 

Otolaryngol. 2020 Jun 3

226. Department of the Army (2009). Programmatic Environmental Assessment for Fielding and Use 

of Mine Resistant Ambush Protected Vehicles at Army Installations in the United States. 

USADOA 2009 Sept. 

227. Department of Defense (2000) Standard Practice for System Safety. DoD, M. I. L. S. T. D. US 

Department of Defense (2000).

228. Department of the Navy (2011) MCO 5100.29B. MCO 5100.298; 2011 Jul

229. Department of the Navy (2015) Marine Corps Hearing Conservation Program 6260.3. Dept of 

Navy 2016;

230. Dept Navy (2009) SecNav Instructions 6120.3 Change Transmittal 1. SECNAVINST 6120.3 CH1; 2009 Dec

231. Dept Navy (2016) Marine Corps Hearing Cons Program 6260.3A. Marines Mil. 2016 Sep;MCO 

6260.3A

232. Dept. of Army (2015) Department of the Army Pamphlet 40Ð501.pdf. (2015) Department of the 

Army Pamphlet 40Ð501

233. DeSpirito & Binseel (2008) Modeling of Acoustic Pressure Waves in Level-Dependent Earplugs.

Army Research Lab 2008; No. ART-TR-4607

234. DeSpirito (2008) Modeling Acoustic Pressure Waves in Level- Dependent Earplugs. ARL 2008 

Sept.

235. DH-132 AS Ballistic Combat Vehicle Helmet. Gentex transaeroinc.com

236. Diamond (2007) The Temporal Dynamics Model of Emotional Memory Processing - StressInduced. Neural Plast. 2007; 2007: 60803

237. Dille (2010) Tinnitus Onset Rates from Chemotherapeutic Agents and Ototoxic AntibioticsResults of a Large Prospective Study.pdf. (2010) Journal of the American Academy of 

Audiology; Volume 21, Number 6, 409-417

238. Dion,G. & Packer, M. (2015) Anaplastic large-cell lymphoma presenting as a nasopharyngeal 

mass and cervical lymphadenopathy. Ear Nose Throat J. 2015 Jun;94(6):E26-9

239. Dixon (1950) Analysis of Extreme Values. The Annals of Mathematical Statistics 1950; 4 (21): 

488-506

240. DOA (2008) DOA - ST 4-02.501 Army Hearing Program. ST 4-02.501; 2008 Feb

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 136 of 171
241. Dobie (2008) The_Burdens_of_Age_related_and_Occupational.pdf. (2008) Ear & Hearing ;29; 

565Ð577

242. Dobie (2016) Commentary on the Regulatory Implication of Noise-induced Cochlear 

Neuropathy. Int J Audiol. 2017;56(sup1):74-78

243. Dobie Medial-Legal Evaluation of Hearing Loss (3rd edition). Plural Publishing Inc, 2015.

244. Dobie, R. (2001) Medical-Legal Evaluation of Hearing Loss (2d Edition). Cengage Learning 

(2001)

245. DOD (2019). DOD Arms Sales Notice

246. DOD Touhy Response re Steady State Exposures. 12.29.2020

247. DoD (2010) Hearing Conservation Program. DoDI 6055.12; 2010 Dec

248. DOD (2003) Directive 5000.01, The Defense Acquisition System. Department of Defense (DoD). 

(2003). The Defense Acquisition System (DoD Directive 5000.01).

249. DoD (2006) Instruction 6025.19 Individual Medical Readiness. Instruction, D. (2006). 6025.19. 

Individual Medical Readiness.

250. DoD (2008) Instruction 5000.02 Operation Defense Acquisition. DoDI 5000.02; 2008 Dec

251. DoD (2011) International State-of- the -Sicence Meeting on Blast-Induced Tinnitus. DoD PCO 

2011

252. DoD (2014) Military Hearing Critical Task Review By Service. Dod HCE

253. DOD Hearing Center of Excellence Video - Hearing Loss and Quality of Life. 

3M_MDL000259866-3M_MDL000259918

254. DoD xxxx NRR Hearing Protection Devices. Dod Lab.

255. Dolan, M., (2004). For 'ghost riders,' Mosul attack a stark reminder of Strykers' mortality. 

Baltimore Sun. 

256. Donahue & Ohlin (1993) Noise and the Impairment of Hearing. Office of the Surgeon General 

U.S. Dept. of the Army 1993; 207-252

257. Donahue (1993) Noise and the Impairment of Hearing. Textbook of Military Medicine: 

Occupational health: the Soldier and the Industrial Base. Washington, DC: Borden Institute, 

Office of The Surgeon General, US Dept of the ArmyÊ(1993): 207-252.

258. Dong (2020) Low-Frequency Repetitive Transcranial Magrnetic Stimulation. Biomed Res Int. 

2020 May 2;2020:3141278

259. Dougherty (2013) Blast-related Ear Injuries among U.S. Military personnel. JRRD 2013; 6 (50): 

893-904

260. Dougherty (2018) Preliminary Study of Hearing Protection and Non-Impact, Blast-Induced 

Concussion in US Military Personnel. Brain Inj. 2018;32(11):1423-142

261. Dougherty (2018) Preliminary study of hearing protection and nonimpact, blast induced 

concussion in US military personnel.pdf. (2018) Brain Injury-32:11, 1423-1428

262. Drolet (2008) Noise dosimetry survey of Land Force occupations.pdf. (2008) Defence R&D 

Canada

263. Duda (2020) Does Tinnitus Fill in the Cap Using Electrophysiology - A Scoping Review. 

Otolaryngol Clin North Am. 2020 Aug;53(4):563-582

264. Dulon (2018) Clarin-1 Gene Transfer Rescues Auditory Synaptopathy in Model of Usher 

Syndrome. J Clin Invest. 2018 Aug 1;128(8):3382-3401

265. Dyhrfjeld-Johnsen (2020) Current Clinical Trials for Tinnitus - Drugs and Biologics. Otolaryngol 

Clin North Am. 2020 Aug;53(4):651-666

266. Engdahl (2015) Cardiovascular risk factors and hearing loss The HUNT study.pdf. (2015) 

International Journal of Audiology, 54:12, 958-966

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 137 of 171
267. EPA (2003) Workshop on Hearing Protector Devices. US Environmental Protection Agency 2003 

Workshop on Hearing Protector Devices Papers and Proceedings

268. Esquivel (2018) Aural Blast Injury Acoustic Trauma and Hearing Loss. Mil Med. 2018 Sep 

1;183(suppl_2):78-82

269. Evaluated Passive Hearing Protection Devices Poster. Hearing Center of Excellence

270. Fackler (2016) Uncertainty of Hearing Protection Device Impulsive Attenuation Measurements. J 

Acoust Soc Am. 2017 May;(141)3687

271. Fackler (2016) Spectral Analysis of Hearing Protector Impulsive Insertion Loss. Int J Audiol. 

2017;56(sup1):13-21

272. Fackler (2017) Spectrual Analysis of Hearing Protector Impulsive Insertion Loss. Int J Audiol. 

2017;56(sup1):13-21

273. Fackler (2018) Fit-testing Systems for Hearing Protectors: ANSI Standards to the Rescue. J 

Acoust Soc Am 2018 Mar; 143

274. Fagelson (1998) The Occlusion Effect and Ear Canal Sound Pressure Level. Am J of Audiol 

1998; 7(2): 50-54

275. Fagelson (2007) The Association Between Tinntus and PTSD. Am J Audiol. 2007 

Dec;16(2):107-17

276. Fagelson (2016) Tinnitus Self Efficacy and Other Tinnitus Self-Report Variables. Ear Hear. 2016 

Sep-Oct;37(5):541-6

277. Fagelson (2016) Tinnitus Self Efficacy and Other Tinnitus Self-Report Variables. Ear Hear. 2016 

Sep-Oct;37(5):541-6

278. Fagelson, M. (2007) The Association Between Tinnitus and PTSD. Am J Audiol. 2007 

Dec;16(2):107-17

279. Fatz (2000) Military Ingenuity DoD hearing conservation efforts help improve readiness and 

provide advanced hearing protection for the armed forces. First ResponderÓ for the 21st 

Century.Ó MasterÕs thesis, USMC Command and Staff CollegeÊ(2005)

280. Faulk (1972) Combined Effects of Noise and Ototoxic Drugs.pdf. (1972) Environmental Health 

Perspectives, 5-72

281. Fausti (1992) High-Frequeney Audiometric Monitoring for Early Detection of Aminoglycoside 

Ototoxicity.pdf. (1992) The Journal of Infectious Diseases. Vol. 165, No. 6 , pp.

282. Fausti (1994) High-Frequency Audiometric Monitoring Strategies for Early Detection of 

Ototoxicity.pdf. (1994) Ear and Hearing Vol. 15, No. 3, 232-239

283. Favrelierea (2020) Drug-induced hearing loss a case non-case study in the French 

pharmacovigilance database.pdf. (2020) Societe Francaise de Pharmacologie et de Therapeutique

284. Fechter (2007) JP-8 Jet Fuel Can Promote Auditory Impairment Resulting from Subsequent 

Noise Exposure in Rats. Toxicol Sci. 2007 Aug;98(2):510-25

285. Fedele (2013) AHAAH hearing Protection Module (Version 2.1) with Level-dependent 

Parameters for the Double-ended Combat Arms Earplug. Army Research Laboratory 2013;

286. Fedele (2013) Using AHAAH with Hearing Protection Software, Release MIL-STD-1474E. 

Army Research Laboratory 2013;

287. Fedele (2015) Level Dependent Nonlinear Hearing Protector Model in the Auditory Hazard 

Assessment Algorithm for Humans. Army Research Laboratory 2015;

288. Fedele, Kalb (2015) Level-Dependent Nonlinear Hearing Protector Hazard Algorithm for 

Humans. US Army Research Lab 2015; TR-7271: 1-33

289. Federal Practitioner (2015) Protecting Sensory Health. Fed Pract. 2015 May;32(5):29

290. Fernandez (2015) Aging After Noise Exposure - Acceleration of Cochlear Synaptopathy in 

Recovered Ears. J Neurosci. 2015 May 13;35(19):7509-20

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 138 of 171
291. Fernandez, K., et al (2020) Noise-induced Cochlear Synaptopathy with and Without Sensory Cell 

Loss. Neuroscience. 2020 Feb; 427:43-57

292. Figueiredo (2016) Positive Association between Tinnitus and Arterial Hypertension.pdf. (2016) 

Frontiers in Cellular Neuroscience Positive Association between Tinnitus and Arterial 

Hypertension, 7:171.

293. Fisher (2020) Noise, Trauma and the Ear. J Laryngol Otol. 2020 Mar;134(3):189-190

294. Flamme (2019) Comparisons of Damage-Risk Criteria (DRC) for Impulsive Noise Evidence from 

Firearm Blast Signals. NIOSH-Report Number EPHB 2019

295. Flamme, G. et al. (2016). Acoustic reflexes are common but not pervasive: evidence from the 

National Health and Nutrition Examination Survey, 1999–2012. International Journal of 

Audiology. 56 (sup1): 52–62

296. Flamme, G. et al. SASRAC Technical Report #1909_0 Pervasiveness of early Middle Ear Muscle 

Contraction, (SASRAC, Loveland OH).

297. Folmer (2010) Audiometric thresholds and prevalence of tinnitus among male veterans in the 

United States.pdf. (2011) Journal of Rehabilitation Research & Development Volume 48, 

Number 5, Pages 503Ð516

298. Foots (2015) Auditory Demonstrations for STEM Outreach. Army Research Laboratory 2015;

299. Formby (2013) Tinnitus Retraining Therapy Trial Manual of Procedures. Clinical Trials 2013;

300. Formby (2019) The Search for and Conduct of the Elusive Phase 3 Randomized Clinical Trial 

Snipe Hunting With the Military. JAMA Otolaryngol Head Neck Surg. 2019 Jul; 145(7):595-596

301. Formby, C. & Scherer, R. (2013) Rationale for the tinnitus retraining therapy trial. Noise Health. 

2013 Mar-Apr;15(63):134-42

302. Forrest, M., and Coles, R. (1970). Problems of communication and ear protection in the royal 

marines. J. R. Nav. Med. Serv., 56, 162-169.

303. Forrest, M.R. (1971), “Ear protection and hearing in high-intensity impulsive noise,” 

Occupational Hearing loss, ed. D.W. Robinson, Academic Press for the British Acoustical 

Society

304. Forshaw, S.E., and J.I. Cruchley (1982), “Hearing protector problems in military operations,” 

Personal Hearing Protection in Industry, ed. P.W. Alberti, Raven Press.

305. Francis (2017) Non-autonomous Cellular Responses to Ototoxic Drug-Induced Stress and 

Death.pdf. (2017) Frontiers in Cellular Neuroscience Non-autonomous Cellular Responses to 

Ototoxic Drug-Induced Stress and Death, 11:252.

306. Franks (1993) Sample size necessary to provide acceptable reproducibility in laboratory hearing 

protector attenuation testing. The Journal of the Acoustical Society of Amer. 1993; 3 (94): 1792-

1792

307. Franks (2009) EPA's Proposed Revision of Hearing Protector Labeling. ISHNN 2009 Oct

308. Franks (2012) Why Choose Custom-Moulded Over Disposable Earplugs. Custom Protect Ear, 

2012 Aug

309. Franks, Merry (1993) Sample Size Necessary to Provide Acceptable Reproducibility of Lab HPD 

Testing. The Journal of the Acoustical Society of America 1993;Ê3 (94): 1792-1792.

310. Franks, Stephenson, Merry, eds. (1996) Preventing Occupational Hearing Loss: A Practical 

Guide. Cincinnati, OH: National Institute for Occupational Safety and Health;

311. Friedland, D. (2006) Structure and Function in the Auditory System - From Cochlear to Cortex. 

Anat Rec A Discov Mol Cell Evol Biol. 2006 Apr;288(4):326-30

312. Frisina (2016) Comprehensive Audiometric Analysis of Hearing Impairment and Tinnitus After 

Cisplatin-Based Chemotherapy in Survivors of Adult-Onset Cancer.pdf. (2016) Journal of 

Clinical Oncology, 34, 23: 2712-2720

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 139 of 171
313. Frye (2018) Lower Level Noise Exposure that Produces only TTS Modulates the Immune 

Homeostasis. J Neuroimmunol. 2018 Oct 15;323:152-166

314. Frye (2019) Inflammation Associated With Noise-Induced Hearing Loss. J Acoust Soc Am. 2019 

Nov;146(5):4020

315. Fuente (2019) Jet Fuel Exposure and Auditory Outcomes in Australian Airforce Personnel. BMC 

Public Health. 2019 May; 19(1):675

316. Fundamental & Clinical Pharmacology 34, 397Ð407

317. Gaeta (2016) Effect of Orifice Shape on Acoustic Impedance. Int J Aeroacoust 2016;15(4-5)474-

495

318. Galazyuck and Brozoski (2020) Animal Models of Tinnitus - A review. Otolaryngol Clin North 

Am. 2020 Aug;53(4):469-480

319. Gallagher (2016) Airforce Research Labs Performance Assessment of the 3M Combat Arms 

Generation 4.0 Tactical Military Shooter's Ear Plug. AFRL. 2016; AFRL-RH-WP-TR-2016-0092

320. Gallun (2012) Performance on Tests of Central Auditory Processing by Individuals Exposed to 

High-Intensity Blasts. J Rehabil Res Dev. 2012;49(7):1005-25

321. Gan (2019) Characterization of Protection Mechanisms to Blast Over pressure for Personal 

Hearing Protection Devices-Biomechanical Measurement and Computational Modeling. Mil 

Med. 2019 Mar; 3/4(184):251-260

322. Ganesan (2018) Ototoxicity A Challenge in Diagnosis and Treatment. J Audiol Otol. 2018 

Apr;22(2):59-68

323. GAO Report - Hearing Loss Prevention Improvements to DOD Hearing Conservation Programs 

Could Lead to Better Outcomes. GAO Report to Congressional Committees 2011; GAO-11-114

324. Gates (2000) Longitudinal Threshold Changes in Older Men with Audiometric Notches. Hear 

Res. 2000 Mar;141(1-2):220-8

325. Gauger (2004) A New Hearing Protector Rating. The Journal of the Acoustical Society of 

America 2004; 5Ê(115): 2378-2378.

326. Geocze, L. et al (2013) Systematic review on the evidences of an association between tinnitus and 

depression. Braz J Otorhinolaryngol. 2013 Jan; 79(1):106-11

327. Gerges (1994) Hearing Protectors. Handbook of Noise and Vibration Control (364Ð376). John 

Wiley & Son, IncÊ(2007).

328. Gerhardt (1987) Ear_Canal_Volume_and_Variability_in_the_Pattems_of Temporary Threshold 

Shifts.pdf. (1987) Ear and Hearing Vol 8, No 6, 316-321

329. Gersten (2020) Ototoxicity and Platinum Uptake Following Cyclic Administration of PlatinumBased Chemotherapeutic Agents.pdf. (2020) JARO DOI: 10.1007/s10162-020-00759-y

330. Gibbs (2006) Comparison of Nondeployable Hearing Profiles by Army Component (Active Duty, 

National Guard, and Reserve) and by Gender. ÊMilitary medicine 2006;Ê10(171): 967-969.

331. Giguere (2014) Exploration of Flat Hearing Protector Attenuation and Sound Detection in Noise. 

The Journal of the Acoustical Society of America 2014; 4 (136): 2165-2166

332. Giguere (2015) Investigation of Hearing Protector Attenuation- Frequency Function on Sound 

Detection and Speech Recognition in Nose. Conference Hearing Research Laboratory uOttawa 

2/19/2015 - 2/21/2015

333. Giguere (2015) Modeling the Interaction between the Hearing Protector Attenuation Function and 

the Hearing Loss Profile on Sound Detection in Noise. Conference: Euronoise 2015; Maastricht, 

The Netherlands

334. Giguere (2016) Speech Recognition in Noise under Hearing Protection: A computational study of 

the combined effects of hearing loss and hearing protector attenuation. Int J Audiol. 2016;55 

Suppl 1: S30-40

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 140 of 171
335. Gittler, J., (2004). Stryker: Bulky fighting vehicle is winning over once-skeptical soldiers. Stars 

and Stripes, December 2004.

336. Gnewikow (2004) Hearing Conservation Lecture-Effects of Noise.pdf

337. Golub (2019) Association of Subclinical Hearing Loss with Cognitive Performance. JAMA 

Otolaryngol Head Neck Surg. 2019 Nov; 146(1):57-67

338. Gonzalez (2017) Noise-Induced Hearing Loss and Tinnitus in Military Personnel. M J E-Med. 

2017 2(2):027

339. Gordon (2017) Audiologic Chacteristics in a Sample of Recently-Separated Military Veterans: 

The Noise Outcomes in Servicemembers Epidemiology Study (NOISE) Study. Hear Res. 2017 

Jun; 349:21-30

340. Grant (2020) Electrophysiological markers of cochlear function correlate with hearing-in-noise 

performance among audiometrically normal subjects. J Neurophysiol. 2020 Aug 1;124(2):418-

431

341. Grantham (2012) Noise-Induced Hearing Loss and Tinnitus: Challenges for the Military. In 

Noise-Induced Hearing Loss 2012; pp. 27-38. Springer, New York, NY

342. Gray, W. (2017) Unintended Relevance: The Role of the Stryker Brigade Combat Team in the 

Decisive Action Environment. 

343. Green (1993) Attenuation Results of a Real-Ear Attenuation at Threshold. AL/CF 1993; 0133: 1-

59

344. Greene (2017) Intracochlear Pressure Measurements during Acoustic Shock Wave Exposure. 

Hear Res. 2018 Aug;365:149-164

345. Greer (2018) Outcomes Associated with Blast Versus Nonblast-related Traumatic Brain Injury in 

US Military Service Members and Veterans: A systematic Review. J Head Trauma Rehabil. 2018 

Mar/Apr;33(2):E16-E29

346. Grobler (2020) Occupational Noise and Age - A Longitudinal Study. S Afr J Commun Disord. 

2020 Mar 17;67(2):e1-e7

347. Groenewold (2011) Severe Hearing Impairment among Military Veterans. MMWR 2011 July; 

(60) 28:955-958

348. Grose (2017) Loud Music and Cochlear Synaptopathy in Young Adults: Isolated Auditory 

Brainstream Response Effects but No Perceptual Consequences. Trends Hear. 2017 Jan-Dec;21

349. Gubata (2013) Pre-enlistment Hearing Loss and Hearing Loss Disability among US soldiers and 

marines. Noise Health 2013; 15 (66): 289-295

350. Guest (2017) Tinnitus with a normal audiogram- Relation to noise exposure but no evidence for 

cochlear synaptopathy. Hear Res. 2017 Feb;344:265-274

351. Guest (2018) Impaired Speech Perception in Noise with a normal audiogram:No 1) evidence for 

cochlear synaptopathy and no relation to lifetime exposure. Hear Res. 2018 Jul; 364:142-151

352. Guest (2019) Reliability and Interrelations of Seven Proxy Measures of Cochlearsynaptopathy. 

Hear Res. 2019 Apr;375:34-43

353. Guida (2014) Evaluation of Hearing Hearing Protection Used by Police Officers in the Shooting 

Range. Braz J Otorhinolaryngol. 2014; 6 (80): 515-521

354. Haase, G. & Rasad, K. (2016) Oxidative Damage and Inflammation Biomarkers - Strategy in 

Hearing Disorders. Otol Neurotol. 2016 Sep;37(8):e303-8

355. Haider (2018) Pathophysiology of Subjective.pdf. (2018) Frontiers in Neuroscience, Volume 12,

Article 866

356. Halford (1991) Anxiety and Depression in Tinnitus Sufferers. J Psychosom Res. 1991;35(4-

5):383-90

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 141 of 171
357. Halford, J. & Anderson, S. (1991) Anxiety and Depression in Tinnitus Sufferers. J Psychosom 

Res. 1991; 35(4-5):383-90

358. Hall (2005) New Directions for Custom Earplugs. Institute of Noise Control EngineeringINTER_NOISE and NOISE-CON Congress and Conference Proceedings 2005; 6 (2005): 2016-

2022

359. Hammil (2019) Role of the US Department of Defense Hearing Center of Excellence in Studying 

the Treatment of Tinnitus. JAMA Otolaryngol Head Neck Surg. 2019 Jul; 145(7):608-609

360. Hammill (2019) I'm Wearing My Hearing Protection- Am I still at risk for hearing loss? Lurking 

Ototoxins in the Military environment. Mil Med. 2019 Mar; 184(Suppl 1):615-620

361. Hammill, T. & Packer, M. (2016) Introduction to the Pharmaceutical Interventions for Hearing 

Loss Clinical Research Guidance Papers. Otol Neurotol. 2016 Sep;37(8):e261-2

362. Hammill, T. (2017) A review of the progress and pitfalls of FDA policy process - Planning a 

pathway for pharmaceutical interventions for hearing loss development. Hear Res. 2017 

Jun;349:172-176

363. Handelsman (2018) Vestibulotoxicity strategies for clinical diagnosis and rehabilitation.pdf. 

(2018) International Journal of Audiology 2018; 57: S69ÐS77

364. Haragopal (2020) Specific loss of neural sensitivity to interaural time difference of unmodulated 

noise stimuli following NIHL. J Neurophysiol. 2020 Aug 26

365. Harrison (2019) Assessing Hidden Hearing Loss after Impulse Noise in a Mouse Model. Noise 

Health. 2019 Jan; 21(98):35-40

366. Hashimoto (2019) Protection from Noise-Induced Cochlear Synaptopathy by Virally Mediated 

Overexpression of NT3. Sci Rep. 2019 Oct 25;9(1):15362

367. Hasoon (2017) Blast-Associated Traumatic Brain Injury in the Military as a Potential Trigger for 

Dementia and Chronic Traumatic Encephalopathy. US Army Med Dep J. 2017 Jan-Jun;(1-

17):102-105

368. Haugnes (2018) Hearing loss before and after cisplatin-based chemotherapy in testicular cancer 

survivors a longitudinal study.pdf. (2018) Hearing loss before and after cisplatinbased 

chemotherapy in testicular cancer survivors: a longitudinal study, Acta Oncologica, 57:8

369. Hawkins, K. et al (2012) The prevalence of hearing impairment and its burden on the qualilty of 

life among adults with Medicare Supplement Insurance. Qual Life Res. 2012 Sep;21(7):1135-47

370. Hearing Center of Excellence 811 (HCE811) Poster - I Waited 9 Months to Hear ''Mommy''. 

3M_MDL000259866-3M_MDL000259918

371. Hearing Center of Excellence (xxxx ) Hearing Protection Devices. Dod HCE; 

https://hearing.health.mil/

372. Hearing Center of Excellence xxxx Aid Your Hearing. Dod HCE; https://hearing.health.mil/

373. Hearing Research (2017). 349. 4-12

374. Hecht (2019) Charaterizatoin of Acute Hearing Changes in the United States Military Populatoin. 

J Acoust Soc Am. 2019 Nov;146(5):3839

375. Heine, C. & Slone, M. (2019) Case studies of adults with central auditory processing disorder -

Shifting the spotlight. SAGE Open Med Case Rep. 2019 Jan 12;7:2050313X18823461

376. Helfer (2003) Postdeployment Hearing Loss in US Army Soldiers Seen at Audiology Clinics 

From April 1, 2003, Through March 31, 2004. American Journal of AudiologyÊ2005; (14): 161-

168

377. Helfer (2010) Epidemiology of Hearing Impairment and Noise-Induced Hearing Injury Among 

U.S. Military Personnel, 2003-2005. Am J Prev Med. 2010 Jan;38(1 Suppl):S71-7

378. Helling, K. et al (2011) Doxycycline reduces ntirc oxide production in guinea pig inner ears. 

Auris Nasus Larynx. 2011 Dec;38(6):671-7

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 142 of 171
379. Henderson (2006) The Role of Oxidative Stress in Noise-Induced Hearing Loss.pdf. (2006) EAR 

& HEARING, VOL. 27 NO. 1

380. Henry (1980) Increased Ototoxicity in Both Young and Old Mice.pdf. (1981) Arch Otolaryngol 

Vol 107, 92-95

381. Henry (2015) Underlying Mechanisms of Tinnitus Review and Clinical Implications.pdf. (2014) 

Journal of the American Academy of Audiology, Volume 25, Number 1

382. Henry (2016) Tinnitus Screener: Results from the first 100 participants in an epidemiology study. 

Am J Audiol. 2016 Jun 1;25(2):153-60

383. Henry (2018) Tramautic Brain Injury and Tinnitus in Military Veterans and Active-Duty Service 

Members. Tinnitus Today 2018 Win.; 10-13

384. Henry (2019) Impact of Tinnitus on Military Service Members. Mil Med. 2019 Mar; 184(Suppl 

1):604-614

385. Henry (2019) Impact of Tinnitus on Military Service Members. Mil Med. 2019 Mar 1;184(Suppl 

1):604-614

386. Henry (2020) Tinnitus - An Epidemiologic Perspective. Otolaryngol Clin North Am. 2020 

Aug;53(4):481-499

387. Henry (2020) Tinnitus - an Epidemiologic Perspective. Otolaryngol Clin North Am. 2020 

Aug;53(4):481-499

388. Henry, J. (2016) Measurement of Tinnitus. Otol Neurotol. 2016 Sep;37(8):e276-85

389. Henry, L., et al (2006) Airway-Obstructing Laryngeal Candidiasis in an Immunocompetent Host. 

Otolaryngol Head Neck Surg. 2005 Nov;133(5):808-10

390. Hertzano (2020) Acoustic Trauma to the Inner Ear. Otolaryngol Clin North Am. 2020 

Aug;53(4):531-542

391. Heupa (2011) Effects of Impact Noise on the Hearing of Military Personnel. Braz J 

Otorhinolaryngol. 2011 Nov-Dec;77(6):747-53

392. Hickman(2018) Blast-induced Cochlear Synaptopathy in Chinchillas. Sci Rep. 2018 Jul 

16;8(1):10740

393. Hickox (2017) Translational Issues in Cochlear Synaptopathy. Hear Res. 2017 Jun;349:164-171

394. Hinkley (2015) Increased striatal functional connectivity with auditory cortex in tinnitus.pdf. 

(2015) Frontiers in Neuroscience, Volume 9, Article 568

395. Hinton (2008) The Multiplex Model of Somatic Symptoms - Tinnitus among Traumatized 

Cambodian Refugees. Transcult Psychiatry. 2008 Jun;45(2):287-317

396. Ho Ahn (2011) Effects_of_Cigarette_Smoking_on_Hearing_Recovery.pdf. (2011) Otol Neurotol 

32:926-932,

397. Hobbs (2009) Wideband Hearing, Intelligibility, and Sound Protection-Tactical Heaset 

Evaluation. The New Yorker, 2009 Feb 6.

398. Hobbs (2008) Wideband Hearing, Intelligibility, and Sound Protection (WHISPr Report)

399. Hocks, K., (2010) Focus On: Hearing Protection. [online] Hearing Review. Available at:

400. Hoffer, M., et al (2013) Neurosensory Sequelae of Mild Traumatic Brain Injury. Psychiatr Ann. 

2013 Jul; 43(7):318-323

401. Hoffmann (2016) A Large Genome-Wide Association Study of Age-Related Hearign 

Impairment. PLoS Genet. 2016 Oct 20;12(10):e1006371

402. HSE (2008) Epidemiological Evidence for the Effectiveness of Noise at Work Regulations. HSE 

Books, Crown (2008)

403. Hsu (2004) Comfort evaluation of hearing protection. International Journal of Industrial 

Ergonomics 2004;33: 543-551

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 143 of 171
404. Hu (2020) Protection of Cochlear Synapses from Noise-Induced Excitotoxic Trauma. Sci U S A. 

2020 Feb 18;117(7):3828-3838

405. Hult (2009) Structural Brain Changes Occuring With Subjecive Tinnitus In Individuals With 

PTSD

406. Humes (2006) Noise and Military Service: Implications for Hearing Loss and Tinnitus

407. Hunter, et al. (2008) Elements of Morphology - Standard Terminology for the Ear. American 

Journal of Medical Genetics Part A 2009;Ê1(149): 40-60.

408. Husain (2020) Perception of, and Reaction to, Tinnitus - the Depression Factor. Otolaryngol Clin 

North Am. 2020 Aug;53(4):555-561

409. International Journal of Audiology (2019). 58(51). 574-580.

410. IOM (2006) Noise and Military Service - Implications for Hearing Loss and Tinnitus. National 

Academy Press 2006

411. Isaacson, J. & Vora, N. (2003) Differential Diagnosis & Treatment of Hearing Loss. Am Fam 

Physician. 2003 Sep 15;68(6):1125-32

412. ISO 9001 : 1994

413. Jafari, Z. et al (2019) Age-related hearing loss and tinnitus, dementia risk and auditory 

amplification outcomes. Ageing Res Rev. 2019 Dec;56:100963

414. Jensen (2015) Immediate and Delayed Cochlear Neuropathy After Noise Exposure in Pubescent 

Mice. PLoS One. 2015 May 8;10(5):e0125160

415. Ji (2019) Auditory Metabolomics, an Approach to Identify Acute Molecular Effects of Noise 

Trauma. Sci Rep. 2019 Jun 25;9(1):9273

416. Jiang (2017) Aminoglycoside-Induced Cochleotoxicity A Review.pdf. (2017) Frontiers in 

Cellular Neuroscience Aminoglycoside-Induced Cochleotoxicity: A Review, 11:308.

417. Job, A., et al (2016) Specific activation of operculum 3 (OP3) brain region during provoked 

tinnitus-related phantom auditory perceptions in humans. Brain Struct Funct. 2016 

Mar;221(2):913-22

418. Johnson (1996) Blast Overpressure Studies with Animals and Man. EG and G Inc. 1993

419. Johnson (1998) Blast Overpressure Studies. USAARL Contract Report N. 1998; CR-98-03

420. Johnson, Patterson (1997) Effectiveness of a Leaking Earmuff vs Leaking Earplug (USAARL 

Report 97-23). USAARL Report 1997; No. 97-23

421. Jokel (2012) Criteria and Procedures for Auditory Health Hazard Assessment of Impulse Noise 

(Blast Over Pressure). U.S. Army Public Health Command Technical Guide No. 338 2012

422. Jokel (2019) Noise of Military Weapons, Ground Vehicles, Planes and Ships. J Acoust Soc Am. 

2019 Nov; 146(5):3832

423. Jones (2015) The Use of Personal Hearing Protection in Hostile Territory and the effect of health 

promotion activity: advice falling upon deaf ears. J R Army Med Corps. 2016; 4 (162): 280-283

424. Jones (2019) Laboratory Evaluation of the Warned Middle-Ear Assumption of the Auditory 

Hazard Assessment Algorithm for Humans (AHAAH). USAARL 2019; 2019-04: 1-16

425. Jones, H et al. (2019). Human middle-ear muscles rarely contract in anticipation of acoustic 

impulses: Implications for hearing risk assessments. Hearing Research. 378: 53–62

426. Joo (2019) Prevalence of Ototoxic Medication Use among Older Adults in Beaver Dam, 

Wisconsin.pdf. (2018) J Am Assoc Nurse Pract.; 30(1): 27Ð34.

427. Joseph, A., et al (2018) Impact of Blast Injury on Hearing in a Screened Male Military 

Population. Am J Epidemiol. 2018 Jan;187(1):7-15

428. Kalb (2010) A hearing protector model for predicting impulsive noise hazard. In Proceedings of 

NOISE-CON 2010; US Army Research Lab, 2010 Apr

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 144 of 171
429. Kalb, Garinther, Golden, Price (1999) ARL-HRED HPD Assessments in Reverberating 

Environments. Army Research Laboratory, Human Research & Engineering Directorate 1999

430. Kamerer (2019) The Role of Cognition in Common Measures of Peripheral Synaptopathy. Am J 

Audiol. 2019 Dec 16;28(4):843-856

431. Kamerer, A. et al (2019) Examining physiological and perceptual consequences of noise 

exposure. J Acoust Soc Am. 2019 Nov;146(5):3947

432. Kaminsky (2017) Drug-Induced Ototoxicity: Mechanisms, Pharmacogenetics, and Protective 

Strategies. Clin Pharmacol Ther. 2017 Apr;101(4):491-500

433. Kaoutar (2020) Why is Drug-Induced Ototoxicity Still Not Preventable nor is it Treatable in.pdf. 

(2020) Why is Drug-Induced Ototoxicity Still Not Preventable nor is it Treatable in 2019? - A 

Literature Review of Aminoglycoside and Cisplatin Ototoxicity. Arch Med Vol: 12 Iss: 2:3

434. Karch (2014) Evaluation of Sound therapy Tinnitus Treatments with Concurent Counseling in 

Active Duty Military Personnel. USAARL 2014;

435. Karch (2016) Hearing Loss and Tinnitus in Military Personnel with Deployment-Related Mild 

Traumatic Brain Injury. US Army Med Dep J. 2016 Oct-Dec;(3-16):52-63

436. Kardous (2004) Limitations of Using Dosimeters in Impulse Noise Environments. Journal of 

Occupational and Environmental Hygiene 2004;Ê7(1); 456-462.

437. Kardous (2018) How Can We Measure Impulse Noise Properly. NIOSH Science Blog 2018

438. Kasden (1976) Changes in Attenuation of Hearing Protectors During Use

439. Kastelein (2017) Temporary Hearing Threshold Shift in a Harbor Porpoise. J Acoust Soc Am. 

2017 Oct;142(4):2430

440. Kaushik (2005) A Review of the Role of Acoustic Sensors in the Modern Battlefield. 11th 

AIAA/CEAS Aeroacoustics ConferenceÊ(p. 2997)

441. Keady (2013) U.S. Patent for Method and Structure for Achieving Spectrum-Tunable and 

Uniform Attenuation. US Patent No. 8,550,206 B2 2013;

442. Keller (2017) Performance in Noise: Impact of Reduced Speech Intelligibility on Sailor 

Performance in a Navy command and control environment. Hear Res. 2017 Jun;349:55-66

443. Khaled (2012) Auditory Backup Alarms -Distance at first detection via in-situ Experimentation 

on alarm design and hearing protection effects. Work. 2012;41 Suppl 1:3599-607

444. Khan (2013) Comparison of Two acoustic Test Fixtures for Measurement of Implulse Peak 

Insertion Loss. HHS - CDC - NIOSH 2014;

445. Khusid, M. (2013) Self-Care Mindfulness Approaches for Refractory Posttraumatic Stress 

Disorder. Psychiatr Ann. 2013 Jul; 43(7):340-344

446. Killion (2011) Better Protection from Blasts without sacrificing situational awareness. Int J 

Audiol. 2011 Mar;50 Suppl 1:S38-45

447. Kim (2018) Osmotic Stabilization Prevents Cochlear Synaptopathy After Blast Trauma. Proc Natl 

Acad Sci U S A. 2018 May 22;115(21):E4853-E4860

448. Kim (2019) The Effect of Earplug Training on Noise Protection. Ann Occup Environ Med. 2019 

Nov 12;31:e34

449. Kim (2020) Associations Between Earplug Use and Hearing Loss in ROK Military Personnel. 

BMJ Mil Health. 2020 Mar 5

450. Kirchner (2012) Occupational Noise-Induced Hearing Loss. JOEM 2012; (54) 1:106-108

451. Kleinjung and Langguth (2020) Abstract Pharmacotherapy of Tinnitus.. Curr Top Behav 

Neurosci. 2020 Aug 7

452. Kobel (2017) Noise-induced cochlear synaptopathy: Past findings and future studies. Hear Res. 

2017 Jun;349:148-154

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 145 of 171
453. Konrad-Martin, D. et al (2016) Serial Monitoring of Otoacoustic Emissions in Clinical Trials. 

Otol Neurotol. 2016 Sep;37(8):e286-94

454. Koochakzadeh (2020) Hearing Outcomes of Treatment for Acute Noise-Induced Hearing Loss. 

Otol Neurotol. 2020 Jul 27

455. Kopke (2002) Enhancing Intrinsic Cochlear Stress Defenses to Reduce Noise-Induced Hearing 

Loss. The Laryngoscope 2002;Ê9 (112): 1515-1532.

456. Kopke (xxxx) A Radical Demise Toxins and Trauma Share Common Pathways in Hair Cell 

Death.pdf. (xxxx) ANNALS NEW YORK ACADEMY OF SCIENCES pages 171-191

457. Kraus and Canlon (2012) Neuronal connectivity and interactions between the auditory and limbic 

systems. Hear Res. 2012 Jun;288(1-2):34-46

458. Krause (2016) Aminoglycosides An Overview.pdf. (2016) Cold Spring Harb Perspect Med; 

6:a027029

459. Kreuzer (2012) Trauma-Associated Tinnitus Audiological Demographic and Clinical 

Characteristics. PLoS One 2012;7(9):e45599

460. Kreuzer (2014) Trauma-associated tinnitus. J Head Trauma Rehabil. 2014 Sep-Oct;29(5):432-42

461. Krishnamurti (2008) Sensorineural Hearing Loss Associated with Occupational Noise Exposure: 

Effects of Age-Corrections. Int. J. Environ. Res. Public Health 2009, (6): 889-899

462. Krishnamurti (2010) Acoustics and Vibration Animations. Ear Hear. 2010 May 24

463. Krishnamurti (2014) FMRI Poster Spring

464. Krishnamurti (2015) Role of Auditory Training in Intervention of Indviduals with Cognitive 

Decline and Hearing Impairment. Perspectives on Gerontology 2015; 2 (20):58

465. Krutt (1980) Attenuation Changes During the Use of Mineral Down and Polymer Foam InsertType Hearing Protectors. Audiology and Hearing Education 1980; 13-14

466. Kubli (2017) The Effects of Repeated Low-level Blast Exposure on Hearing in Marines. Noise 

Health. 2017 Sep-Oct;19(90):227-238

467. Kujawa, S. & Liberman, C. (2006) Acceleration of Age-Related Hearing Loss by Early Noise 

Exposure -Evidence of Misspent Youth. J Neurosci. 2006 Feb 15;26(7):2115-23

468. Kujawa, S. & Liberman, C. (2009) Adding Insult to Injury - Cochlear Nerve Degeneration after 

Temporary Noise-Induced Hearing Loss. J Neurosci. 2009 Nov 11;29(45):14077-85

469. Kujawa, S. & Liberman, M.C. (2015) Synaptopathy in the noise-exposed and aging cholea -

primary neural degeneration in acquired sensorineural hearing loss. Hear Res. 2015 Dec; 330(Pt 

B):191-9

470. Kurabi (2017) Cellular Mechanisms of noise-induced hearling loss. Hear Res. 2017 Jun;349:129-

137

471. Kusy & Chatillion (2012) Real-world Attenuation of Custom-moulded Earplugs Results from 

Industrial in situ F-MIRE Measurements. Appl. Acoust. 2012 (73): 639-647

472. Kyle (2015) Impact of Nonaspirin Nonsteroidal Anti-inflammatory Agents and Acetaminophen 

on Sensorineural Hearing Loss - A Systematic Review.pdf. (2015) Otolaryngol Head Neck Surg.; 

152(3): 393Ð409

473. Laborers ACG (2000) Hearing Protection. Proceedings of the 11 th International Congress on 

Noise as a Public Health Problem. 2011.

474. Langer (2013) Understanding platinum-induced ototoxicity.pdf. (2013)Trends in 

Pharmacological Sciences, Vol. 34, No. 8

475. Langguth (2020) Non-Invasive Neuromodulation for Tinnitus. J Audiol Otol. 2020 Jul;24(3):113-

118

476. Lawson, B., et al (2013) Mental Disorders Comorbid with Vestibular Pathology. Psychiatr Ann. 

2013 Jul; 43(7):324-327

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 146 of 171
477. Le (2017) Current insights in noise induced hearing loss a literature review of the underlying 

mechanism.pdf. (2017) Journal of Otolaryngology - Head and Neck Surgery - 46:41

478. Le Prell (2017) Effects of Noise on Speech Recognition Challenges for Communication by 

Service Members. Hear Res. 2017 Jun;349:76-89

479. Le Prell (2019) Effects of Noise Exposure on Auditory Brainstem Response and Speech-in Noise 

Tasks. Int J Audiol. 2019 Feb;58(sup1):S3-S32

480. Le Prell (2019) Noise-Induced Hearing Loss and its Prevention. J Acoust Soc Am. 2019 

Nov;146(5):4051

481. Le Prell (2019) Noise-Induced Hearing Loss: Translating risk from animal models

482. Le Prell, C. & Brungart, D. (2016) Speech-in-Noise Tests and Supra-threshold Auditory Evoked 

Potentials as Metrics for Noise Damage and Clinical Trial Outcome Measures. Otol Neurotol. 

2016 Sep;37(8):e295-302

483. Le, T. et al (2017) Current insights in noise-induced hearing loss - a literature review of 

underlying mechanism, pathophysiology, asymmetry, etc. J Otolaryngol Head Neck Surg. 2017 

May 23;46(1):41

484. Leaver, A. et al (2011) Dysregulation of limbic and auditory networks in tinnitus. Neuron. 2011 

Jan 13;69(1):33-43

485. Lee, T., et al. (2009) Growth Inhibitory and Anti-Tumour Activities of OSU-03012, Novel PDK1 Inhibitor.... Eur J Cancer. 2009 Jun;45(9):1709-20

486. Lefebvrea (2002) _Mechanisms of Cell Death in the Injured Auditory System Otoprotective 

Strategies.pdf. (2002) Audiol Neurootol;7: 165Ð170

487. Lehtomaki (2000) Noise Attenuation against Heavy Weapon Noise. Military medicine 200; 9 

(165): 678-682.

488. LePrell (2017) Effects of noise on speech recognition - Challenges for communication by service 

members. Hear Res. 2017 Jun;349:76-89

489. Letowski (1998) Speech Communication with Flat-Attenuation Hearing Protectors. Institute of 

Noise Control Engineering-INTER_NOISE and NOISE-CON Congress and Conference 

Proceedings 1998; 4 (1998): 1261-1264

490. Levy (2020) Cochlear Implantation for Treatment of Tinnitus in Single-sided Deafness. Cochlear 

Implants Int. 2011 May;12 Suppl 1:S26-9

491. Lewis (2020) Audiometric Predictors of Bothersome Tinnitus in a Large Clinical Cohort of 

Adults With Sensorineural Hearing Loss. Otol Neurotol. 2020 Apr;41(4):e414-e421

492. Li (2018) Deletion of Tmtc4 Activates the Unfolded Protein Response Causing Postnatal Hearing 

Loss. J Clin Invest. 2018 Nov 1;128(11):5150-5162

493. Liberman (2015) Dynamics of Cochlear Synaptopathy After Acoustic Overexposure. J Assoc Res 

Otolaryngol. 2015 Apr;16(2):205-19

494. Liberman (2016) Toward a Differential Diagnosis of Hidden Hearing Loss in Humans. PLoS 

One. 2016 Sep 12;11(9):e0162726

495. Liberman (2017) Cochlear synaptopathy in acquired sensorineural hearing loss: Manifestations 

and Mechanisms. Hear Res. 2017 Jun;349:138-147

496. Lin (2011) Hearing Loss Prevalence in the United States.pdf. (2011) Arch Intern Med.; 171(20): 

1851Ð1852

497. Lin (2020) Cigarette Smoking, Smoking Cessation, and Risk of Hearing Loss in Women.pdf. 

(2020) The American Journal of Medicine 000:1 7

498. Lin, F. et al (2011) Hearing Loss Prevalence in the United States. Arch Intern Med. 2011 Nov 

14;171(20):1851-2

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 147 of 171
499. Lindqvist (2002) Field Investigation Real- World Attenuation provided by insert-type hearing 

protectors. Medicinska Fakulteten-Lunds Universitet-Institutionen for Logopedi, foniatri och 

audiologi

500. Liu (2012) Case Report - Irreversible Atorvastatin-Associated Hearing Loss.pdf. (2012) Case 

Report - Irreversible Atorvastatin-Associated Hearing Loss

501. Liu (2016) Noise induced hearing loss impairs spatial learning memory and hippocampal 

neurogenesis in mice. Sci Rep. 2016 Feb 4;6:20374

502. Liu (2019) Functional alteration of ribbon synapses in inner hair cells by noise exposure causing 

hidden hearing loss. Neurosci Lett. 2019 Aug; 707:134268

503. Lobarinas (2016) Differential Effects of Suppressors on Hazardous Sound Pressure Levels 

Generated by AR-15 Rifles: Considerations for recreational shooters, law enforcement, and the 

militaryy. Int J Audiol. 2016;55 Suppl 1:S59-71

504. Lobarinas (2017) Evidence of Òhidden hearing loss "following noise exposures that produce 

robust TTS and ABR waveÑ1 amplitude reductions. Hear Res. 2017 Jun;349:155-163

505. Lopez-Escamez (2020) Heritability and Genetics Contributioni to Tinnitus. Otolaryngol Clin 

North Am. 2020 Aug;53(4):501-513

506. Lopez-Poveda (2019) Primary Neural Degeneration in the Human Cochlea Evidence for.pdf. 

(2019) Neuroscience- 8-20

507. Loprinzia (2017) Relationship Between Objectively Measured Physical Activity, Cardiovascular 

Disease Biomarkers, and Hearing Sensitivity.pdf. (2017) American Journal of Audiology Vol. 26, 

163Ð169

508. Lovejoy (2007) Hearing Protection Evaluation for the Combat Arms Earplug at Idaho National 

Lab March 2007. INL 2007 March

509. Lovejoy (2007) Lovejoy-Impulse- Hearing protection evaluation for the combat arms earplug at 

Idaho National Laboratory. INL 2007 March

510. Luetzenberg (2020) Alternative Treatment of Tinnitus - Alternative Medicine. Otolaryngol Clin 

North Am. 2020 Aug;53(4):637-650

511. Lukas (2006) Free-field Sound Localization with Non-Linear Hearing Protection Devices

512. Luo (2020) Repeated Moderate Sound Exposure Causes Accumulated Trauma to Cochlear 

Ribbon Synapses in Mice. Neuroscience. 2020 Mar; 429:173-184

513. Lustig (2001) Molecular Cloning and Mapping of the Human Nicotinic Acetylcholine Receptor 

alpha10 CHRNA 10. Genomics. 2001 May 1;73(3):272-83

514. Lustig (2006) Nicotinic Acetylcholine Receptor Structure and Function in the Efferent Auditory 

System. Anat Rec A Discov Mol Cell Evol Biol. 2006 Apr;288(4):424-34

515. Lustig (2018) Disease and Targets for Local Drug Delivery to the Inner Ear. Hear Res. 2018 

Oct;368:3-9

516. Ma (2018) Extended High-Frequency Audiometry (9Ð20 kHz) in Civilian Pilots.pdf. (2018) 

Aerospace Medicine and Human Performance Vol. 89, No. 7, 593-600

517. MacGregor (2020) Co-Occurrence of Heairng Loss and posttraumatic stress disorder among 

injured military personnel: a retrospective study. BMC Public Health. 2020 Jul; 20(1):1076

518. MacGregor (2020) Co-occurrence of hearing loss and posttraumatic stress disorder among injured 

military personnel a retrospective study. BMC Public Health. 2020 Jul 8;20(1):1076

519. MacGregor (2020) Co-occurrence of Hearing Loss and Posttraumatic Stress disorder Among 

Injured Military Personnel A Retrospective Study. BMC public health 2020; 1 (20): 1-7

520. MacGregor, A., et al (2020) Prevalence of Tinnitus and Association with Self-Rated Health 

among Military Personnel Injured on Combat Deployment. Mil Med. 2020 Sep 18;185(9-

10):e1608-e1614

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 148 of 171
521. Maeda (2020) Immediate Changes in Transcription Factors and Synaptic Transm in the Cochlea 

Following Acoustic Tra. Neurosci Res. 2020 May 15:S0168-0102(20)30106-1

522. Mahoney (2011) Structural neuroanatomy of tinnitus and hyperacusis in semantic dementia. J 

Neurol Neurosurg Psychiatry. 2011 Nov;82(11):1274-8

523. Manning (2017) The effect of sensorineural hearing loss and tinnitus on speech recognition over 

air and bone conduction military communications headsets. Hear Res. 2017 Jun; 349:67-7

524. Manning (2019) Perception Versus Reaction: Comparison of Tinnitus Psychoacoustic Measures 

and Tinnitus Functional Index Scores. Am J Audiol. 2019 Apr; 28(1S):174-180

525. Marmel (2020) The Ongoing Search for Cochlear Synaptopathy in Humans. Hear Res. 2020 Jul;

392:107960

526. Martinez (2012) Can you Hear Me Now- Occupational hearing loss, 2004-2010. Monthly Lab. 

Rev. 2012; (135) 48

527. Martz, E., et al (2018) Tinnitus, Depression, Anxiety, and Suicide in Recent Veterans - A 

Retropective Analysis. Ear Hear. 2018 Nov/Dec;39(6):1046-1056

528. Matsumura, J., et al., (2017). Assessing tracked and wheeled vehicles for Australian Mounted 

Close Combat Operations

529. Mazurek (2012) Stress and tinnitus. Front Syst Neurosci. 2012 Jun 11; 6:47

530. McBride (2001) Audiometric notch as a sign of noise induced hearing loss. Occupational and 

Environmental MedicineÊ2001; 1 (58): 46-51.

531. McFadden (1982) Aspirin can potentiate the temporary hearing loss induced by intense 

sounds.pdf. (1983) Heuring Research, 9 295-316

532. McFerran (2018) Drugs_and_tinnitus_Ver_2.3.pdf

533. McGwin Jr. (2010) Phosphodiesterase Type 5 Inhibitor Use and Hearing Impairment.pdf. (2010) 

Arch Otolaryngol Head Neck Surg.;136(5):488-492

534. McIlwain (2008) Evolution of the Army Hearing Program. US Army Med Dep J. 2008 AprJun:62-6

535. McIlwain (2008) Heritage of Army Audiology and the Road Ahead: The Army Hearing Program. 

Am J Public Health. 2008 Dec;98(12):2167-72

536. McKee (2014) Military-related traumatic brain injury and neurodegeneration. Alzheimers 

Dement. 2014; 3 Suppl (10): S242-S253

537. McKenna (2014) A scientific congitive-behavioral model of tinnitus. Front Neurol. 2014 Oct 6;

5:196

538. McKenna (2020) Current Validated Medical Treatments for Tinnitus. Otolaryngol Clin North 

Am. 2020 Aug;53(4):605-615

539. McKenna, et al (2014) A Scientific cognitive-behavioral model of tinnitus - novel 

conceptulizations of tinnitus distress. Front Neurol. 2014 Oct; 5:196

540. McKinley (2000) Military Noise Environments and Hearing Protection/Conservation. Air Force 

Research Laboratory 2020

541. McKinley (2005) Improved Hearing Protection Aviation Personnel. AIR FORCE RESEARCH 

LAB WRIGHT-PATTERSON AFB OH

542. McKinley (2004) Passive Hearing Protection Systems. RTO-EN-HFM-111 2004: 1-13

543. McKinley, R, Gallagher, H., Murphy, WJ (2012) Using impulsive peak insertion loss of hearing 

protectors with impulsive damage risk criteria, Presentation in The Journal of the Acoustical 

Society of America · May (USAFRL and NIOSH)

544. McKinley, R., Gallagher, H., (2012) Using impulsive peak insertion loss of hearing protectors 

with impulsive damage risk criteria. Presentation in The Journal of the Acoustical Society of 

America · May (163rd Meeting of the Acoustical Society of America)

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 149 of 171
545. McKinley, Richard L. (2010), ”Auditory and acoustic research and development at the Air Force 

Research Laboratory,” Acoustics Today, page 22

546. Meehan (2019) Hidden hearing deficits in military service members with persistent post 

concussive symptoms. Undersea Hyperb Med. 2019 BIMA Special Edition No. Feb;46(3):251-

260

547. Megarbane & Fuente (2020) Association between speech perception in noise and 

electrophysiological measures. Int J Audiol. 2020 Jun;59(6):427-433

548. Megha (2019) Narrow-band Chirp and Tone Burst Auditory Brainstem Response. Intractable 

Rare Dis Res. 2019 Aug;8(3):179-186

549. Mehraei (2016) Auditory Brainstem Response Latency in Noise as a Marker of Cochlear 

Synaptopathy. J Neurosci. 2016 Mar 30;36(13):3755-64

550. Meinke (2017) Prevention of Noise-Induced Hearing Loss from Recreational Firearms. Semin 

Hear. 2017 Nov;38(4):267-281

551. Memo re CAEv2 and CAEv3 Military Testing

552. Mepani (2019) Middle Ear Muscle Reflex and Word Recognition in Normal-Hearing Adults. Ear 

Hear. 2020 Jan/Feb;41(1):25-38

553. Merry et al (1992) The Effect of Fitting Procedure on Hearing Protector Attenuation. Ear and 

Hearing 1992; 1 (13): 11-17

554. Miao (2019) An Overview of Research Trends and Genetic Polymorphisms for NIHL. Environ 

Sci Pollut Res Int. 2019 Dec;26(34):34754-34774

555. Michel (2014) On the scaling of jet noise with Helmholtz Number close to the jet axis. 20th 

AIAA/CEAS Aeroacoustics Conference June 2014

556. MIL-DTL-44117B. Military Specification Helmet, Combat Vehicle Crewman, Ballistic Shell, 

DH-132B.

557. Military.com. M1126 Stryker Combat Vehicle

558. Mirza (2018) Occupational Noise-Induced Hearing Loss. J Occup Environ Med. 2018 Sep; 60(9): 

498-501

559. Mohrle (2019) Enhanced Central Neural Gain Compensates. Neuroscience. 2019 May 21;

407:146-169

560. Moore (2019) Incidence Rates of Tinnitus in Active Duty Military Service Members Between 

2001 and 2015.pdf. (2019) American Journal of Audiology Vol. 28, 866Ð876

561. Moore (2020) Diagnosis and quantification of military noise-induced hearing loss. J Acoust Soc 

Am. 2020 Aug;148(2):884

562. Moore, B. et al (2019) Incidence Rates of Tinnitus in Active Duty Military Service Members 

Between 2001 & 2015. Am J Audiol. 2019 Dec 16;28(4):866-876

563. Morata (2001) Factors affecting hearing protectors in a population of printing workers. Noise and 

HealthÊ2001; 13 (4): 25.

564. Morata, TC, et al (1993) Effects of occupational exposure to organic solvents & noise on hearing. 

Scand J Work Environ Health. 1993 Aug;19(4):245-54

565. More (2010) Role of the Copper Transporter, CTR1, in Platinum-Induced Ototoxicity. J 

Neurosci. 2010 Jul 14;30(28):9500-9

566. Moring (2017) Tinnitus,Traumatic Brain Injury, and Post traumatic Stress Disorder in the 

Military. Int J Behav Med. 2018 Jun;25(3):312-321

567. Morse (2007) Using sound pressure to estimate reaeration in streams. J.N. Am. Benthol. Soc 

2007, 26(1):28-37

568. Mosko, J.D., and Fletcher, J.L. (1971). Evaluation of the Gunfender earplug: temporary threshold 

shift and speech intelligibility. Journal of the Acoustical Society of America. 49, 1732-1733.

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 150 of 171
569. Mozeika (2020) Opioid-Associated Hearing Loss A 20-Year Review from the New Jersey Poison 

Center.pdf. (2019) Journal of Medical Toxicology

570. Mozo, B., Murphy, B., & Barlow, L. (1992). Sound Attenuation Characteristics of the DH-133A 

Helmet. J.N. Am. Benthol. Soc 2007, 26(1): 28-37. 

571. Mrena (2008) The effect of improved hearing protection regulations in the prevention of military 

noise-induced hearing loss. Acta Otolaryngol. 2008 Sep;128(9):997-1003

572. Mrena, R., et al (2004) Otologic Consequences of Blast Exposure - A Finnish Case Study of a 

Shopping Mall Bomb Explosion. Acta Otolaryngol. 2004 Oct;124(8):946-52

573. Muhr (2019) Abstract Noise Exposure and Hearing Impairment in Air Force Pilots - PubMed. 

Aerosp Med Hum Perform. 2019 Sep 1;90(9):757-763.

574. Mukjerjea (2012) The Design and Screening of Drugs to Prevent Acquired.pdf. (2011) Expert 

Opin Drug Discov.; 6(5): 491Ð505.

575. Mulrow, C., et al (1990) Quality-of-life Changes and Hearing Impairment. A Randomized Trial. 

Ann Intern Med. 1990 Aug;113(3):188-94

576. Munjal (1997) Impulse Noise Trauma During Army Weapon Firing.pdf. (1997) IJ & HNS-Vol 49 

No.2

577. Murphy (2003) Development of a new standard laboratory protocol for estimation of the field 

attenuation of hearing protection devices: Sample size necessary to provide acceptable 

reproducibility. The Journal of the Acoustical Society of America 2003;1Ê(115): 311-323.

578. Murphy (2006) Results from the National Institute for Occupational Safety and Health 

Administration/Environmental Protection Agency (NIOSH/EPA) interlaboratory comparison of 

American National Standards. NIOSH/EPA Interlab Stud Comparison of ANSI S12.6 Method A 

and B

579. Murphy (2009) An Analysis of the Blast Overpressure Study Data Comparing Three Exposure 

Criteria. NIOSH-Report Number EPHB 2009

580. Murphy (2010) Hands-on fit-testing.. NHCA Spectrum Conference 2010 Jan

581. Murphy (2012) Comparison of three acoustic test fixtures for impulse peak insertion loss slides. J. 

Acoust. Soc. Am. 2011; (130) 4: 2433

582. Murphy (2012) Measurement of Impulse Peak Insertion Loss for Four Hearing Protection 

Devices in field conditions. Int J Audiol. 2012 Feb;51 Suppl 1(0 1):S31-42

583. Murphy (2012) Peak Reductions of Nonlinear Hearing Protection Devices. 2003 Apr

584. Murphy (2014) Comparison impulse peak insertion loss measured with gunshot and shock tube 

noise sources. The Journal of the Acoustical Society of America 2014; 4 (136): 2165-2166

585. Murphy (2015) Comparison of the Performances of Three Acoustic Test Fixtures Using Impulse 

Peak Insertion Loss Measurements. EPHB Report 2015; 350(14a): 1-40

586. Murphy (2016) Angle Dependent Effects for Impulsive Noise Reduction for Hearing Protectors. 

Proc Mtgs Acoust. 2016;1(29):040010

587. Murphy et al. (2009) Results NIOSH. J. Acoust. Soc. Am. 2009 May; (125) 5

588. Murphy et al. (2012) Measurement of impulse peak insertion loss for four hearing protection 

devices in field conditions. International Journal of Audiology 2012; 51: S31—S42

589. Murphy et al. (2015) Measurement impulse peak IL. International Journal of Audiology 2012; 

Sup 1 (51): S31-S42

590. Murphy W.J. et al.(2009) An analysis of the blast overpressure study data comparing three 

exposure criteria. Survey Report EPHB 309-05H. National Institute for Occupational Safety and 

Health. Cincinnati, OH (December 2009).

591. Murphy WJ and Tubbs R.L. (2007) Assessment of noise exposure for indoor and outdoor firing 

ranges. J Occ Env Hyg, 4, 688-697

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 151 of 171
592. Murphy, William James (2012), ”A case for using A-weighted equivalent energy as a damage 

risk criterion for impulse noise exposure,” The Journal of the Acoustical Society of America.

593. Murphy, William James (2015), ”Protecting hearing from impulsive noise,” NHCA Spectrum, 32.

594. Murphy, WL et al., (2015) NIOSH Comparison of Performance of Three Acoustic Test Fixtures 

Using Impulse PEak Insertion Loss Measurements. EPHB Report 350-14a.

595. Musiba (2020) Classification of Audiograms in the Prevention of Noise-Induced Hearing Loss -

A Clinical Perspective. S Afr J Commun Disord. 2020 Mar 3;67(2):e1-e5

596. Naert (2019) Use of the Guinea Pig in Studies on the Development and Prevention of acquired 

sensorineural hearin. J Acoust Soc Am. 2019 Nov;146(5):3743

597. Nakashima (2010) Overview of Tactical Communication Headsets. DRDC Toronto TM 2010-

003; 2010 Jan

598. Nakashima (2010) Overview of Tactical Communication Headsets. Defense Research and 

Development Toronto 2010;

599. Nakashima (2015) Review of Weapon Noise Measurement and Damage Risk Criteria: 

Considerations for Auditory Protection and Performance. Military Medicine 2015; 4 (180): 402-

408

600. Nakashima (2015) Comparison of different types of hearing protection devices for use during 

weapons firing. Journal of Military, Verteran and Family Health 2015; 1(2):43-51

601. Nakashima (2015) A comparison of metrics for impulse noise exposure. Defendse Research and 

Development Canada 2005; DRDC-RDDC-2015-R243

602. Nakashima, A., et al (2007) Hearing, communication and cognition in low-frequency noise from 

armored vehicles. Noise Health. 2007 Apr-Jun;9(35):35-41

603. NATO (2000) Damage Risk from Impulse Noise. SERIES, RTO LECTURE (2000).

604. NATO (2005) New Directions Improving Audio Effectiveness. TREATY, N. A. New Directions 

for Improving Audio Effectiveness 2005.

605. NATO (2001) Reconsideration of the Effects of Impulse Noise. RTO TR-017 2003

606. NATO (2005) Personal Hearing Protection including Acvite Noise Reduction. EN-HFM, R. E. N. 

Personal Hearing Protection including Active Noise Reduction.

607. NATO (2017) Hearing Protection - Needs, Technologies, and Performance. RTO TR-HFM-147 

2010

608. Navy (2003) MCO P1020.34G CH 1-5. Department of the Navy 2003 MCO P1020.34G CH 1-5

609. Navy (2006) NAVMC directive 5100.8. Marine Corps Occupational Safety and Health (OSH) 

Program Manual; 2006

610. Navy (2007) NAVMC directive 5040.6H. Marine Corps Readiness Inspections and Assessments 

Manual; March 2007

611. Navy (2008) MCO 5200.24D. MCO 5200.24D; 2008 Mar

612. Navy (2017) BUMEDINST 6270.8C. Department of the Navy Bureau of Medicine and Surgery 

2017 May

613. Navy Marine Corps (2005) Mishap and Safety Investigation, Reporting, and Record Keeping 

Manual Ch. 2. Navy Marine Corps (2005) Mishap and Safety Investigation, Reporting, and 

Record Keeping Manual Ch. 2

614. Navy Med Dept (2008) Hearing Cons Program. NMCPHC - TM 6260.51.99-2; 2008 Sept

615. Navy_2012 _BUMEDINST 6110.14 CH-1, CH-2, and CH-3. BUMEDINST 6110.14

616. NCMJ (2017) Introduction to the NCMJ's Special Issue on Vision and Hearing Loss. N C Med J. 

2017 Mar-Apr;78(2):93-95.

617. Neitzel (2006) Variability Real-World Hearing Protector Attenuation Measurements. Ann Occup 

Hyg. 2006 Oct;50(7):679-91

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 152 of 171
618. Nelson (2010), “Senior Scientific Advisor Earns Fellow Standing,” Wright-Patterson AFB, 

https://www.wpafb.af.mil/News/Article-Display/Article/400002/senior-scientific-advisor-earnsfellow-standing/.

619. Nelson (2017) Hearing Testing in the US DoD: Potential Impact on Veterans Affairs Hearing 

Loss Disability Awards. Hear Res. 2017 Jun;349:13-20

620. Nelson, A., et al (2013) Cerebral Vasospasm in traumatic Brain Injury - A Case Study. Psychiatr 

Ann. 2013 Jul; 43(7):328-330

621. Ness (xxxx) Documenting, Recording, and Reporting of Adverse Events and Unanticipated 

Problems.pdf

622. New Perspectives on Protecting Hearing from Intense Impulse Noise. PRICESUBPOENA0091-

PRICESUBPOENA0026

623. NHCA xxxx Fitting Hearing Protection. NHCA; Guide''2: https://www.hearingconservation.org/

624. NHCA xxxx Selecting Hearing Protection. NHCA; Guide''1: 

https://www.hearingconservation.org/

625. NICE (2020) Tinnitus - Assessment and Management - Evidence Review A. London: National 

Institute for Health and Care Excellence (UK); 2020 Mar

626. NICE (2020) Tinnitus - Assessment and Management - Evidence Review for Assessing 

Psychological Impact. London: National Institute for Health and Care Excellence (UK); 2020 

Mar

627. NICE (2020) Tinnitus - Assessment and Management - Evidence Review for Assessing Quality 

of Life. London: National Institute for Health and Care Excellence (UK); 2020 Mar

628. NICE (2020) Tinnitus - Assessment and Management - Evidence Review for Audiological 

Assessment. London: National Institute for Health and Care Excellence (UK); 2020 Mar 11

629. NICE (2020) Tinnitus - Assessment and Management - Evidence Review for Combinations of 

Management Strategies. London: National Institute for Health and Care Excellence (UK); 2020 

Mar

630. NICE (2020) Tinnitus - Assessment and Management - Evidence Review for Neuromodulation. 

London: National Institute for Health and Care Excellence (UK); 2020 Mar

631. NICE (2020) Tinnitus - Assessment and management - Evidence Review for Psychoacoustic 

Measures. London: National Institute for Health and Care Excellence (UK); 2020 Mar

632. NICE (2020) Tinnitus - Assessment and Management - Evidence Review for Psychological 

Therapies. London: National Institute for Health and Care Excellence (UK); 2020 Mar

633. NICE (2020) Tinnitus - Assessment and Management - Evidence Review for Questionnaires to 

Assess Tinnitus. London: National Institute for Health and Care Excellence (UK); 2020 Mar

634. NICE (2020) Tinnitus - Assessment and Management - Evidence Review for Sound Therapy and 

Amplification Devices. London: National Institute for Health and Care Excellence (UK); 2020 

Mar

635. NICE (2020) Tinnitus - Assessment and Management - Evidence Review Review for Patient 

Information. London: National Institute for Health and Care Excellence (UK); 2020 Mar

636. NICE (2020) Tinnitus - Assessment and Management. London: National Institute for Health and 

Care Excellence (UK); 2020 Mar

637. NIOSH (1975) List of Personal Hearing Protectors and Attenuation Data (PB 267-461). US 

Department of Health, Education, and Welfare, Public Health Service, Center for Disease 

Control, National Institute for Occupational Safety and Health, Division of laboratories and 

Criteria Development, 1975

638. NIOSH (1998) Criteria for a Recommended Standard - Occupational Noise Exposure. NIOSH 

1998

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 153 of 171
639. NIOSH (2003) Noise Hazard Evaluation Report March

640. NIOSH Science Blog - How Can We Measure Impulse Noise Properly. NIOSH Science Blog 

2018-https://blogs.cdc.gov/niosh-science-blog/2018/07/18/impulse-noise/

641. Niquette (2007) The Hearing Review: Uniform Attenuation Hearing Protection Devices. The 

Hearing Review 2007 March: 42-45

642. Nixon (1998) A Glimpse of History: The Origin of Hearing Conservation Was in the Military?. 

AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH HUMAN EFFECTIVENESS 

DIRECTORATE, 1998.

643. Noise Health and Environmental Standards - Various Article. Sessions

644. Nondahl (2002) Prevalence and 5-year incidence of tinnitus among older adults-The 

epidemiology of hearing loss study.pdf. (2002) Journal of the American Academy of Audiology, 

13 : 323-331

645. Nondahl (2010) The ten year incidence of tinnitus among older adults.pdf. (2010) The ten-year 

incidence of tinnitus among older

646. Nondahl (2011) Tinnitus and its Risk Factors in the Beaver Dam Offspring Study.pdf. (2011) 

International Journal of Audiology.; 50(5): 313Ð320.

647. Norena (2015) Revisiting the Cochlear and Central Mechanisms of Tinnitus and Therapeutic 

Approaches. Audiol Neurootol. 2015;20 Suppl 1:53-9

648. Norin (2011) Speech Intelligbility and passive, level-dependent earplugs. Ear Hear. 2011 SepOct;32(5):642-9

649. Now Hear This (2006) Noise and Military Service. Now Hear This. 2006 (9):1

650. Oestenstad (2008) Efficacy Army policy hearing cons programs. Mil Med. 2008;173(10):992

651. Ohlin (2000) Cost Effectiveness of Hearing Conservation Programs. ARMY CENTER FOR 

HEALTH PROMOTION AND PREVENTIVE MEDICINEÊ2000

652. Ohlin (1994) Best Practices in Hearing Loss Prevention. Textbook of Military Medicine: 

Occupational health: the Soldier and the Industrial Base. Washington, DC: Borden Institute, 

Office of The Surgeon General, US Dept of the Army, 207-252.

653. Ohlin (2009) Strategic Tactical Thinking in the hearing conservation mindset: A military 

perspective. Noise Health. 2009 Jan-Mar;11(42):22-5

654. Ohlin (2010) Hearing Protection: It's not just about Noise Reduction. EHS Today; 2019 Apr 12

655. Ohlin (2011) Get Stupid Stuff Right - Checklists benefit hearing conservation. ISHN 2011 Nov 1

656. Ohlin-Fatz Publication re Army-Improved CAEv2. Occupational Health and Safety 2000; 6 (69): 

101-102

657. OHSU (2008) TINNITUS FUNCTIONAL INDEX.pdf

658. Okpala (2007) Knowledge and Attitude of Infantry soldiers to hearing conservation. Mil Med. 

2007 May;172(5):520-2

659. Oleksiak (2012) Audiological issues and hearing loss among veterans with mild traumatic brain 

injury. J Rehabil Res Dev. 2012;49(7):995-1004

660. Oliveira (1997) The Active Earcanal. J. Am. Acad. Audiol. 1997; 6 (8): 401-410

661. Onge (2011) Marine Corps Breacher training study - auditory and vestibular findings. US Army 

Med Dep J. 2011 Jul-Sep:97-107

662. OSHA (2002) Hearing Conservation 3074 (Revised). OHSHA 2002 OHSHA Publication 3074

663. OSHA xxxx Occupational noise exposure CFR 1910.95. OSHA; 1910.95G:1-9 www.OSHA.gov

664. Osman (2008) Muscle-Like Nicotinic Receptor Accessory Molecules in Sensory Hair Cells of the 

Inner Ear. Mol Cell Neurosci. 2008 Jun;38(2):153-69

665. Ou (2017) Development o fa Shortened Version of the Spatial Hearing Questionnaire (SHQ-S) 

B378 for Screening Spatial-Hearing Ability. Am J Audiol. 2017 Sep 18;26(3):293-300

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 154 of 171
666. Oxenham (2016) Predicting the Perceptual Consequences of Hidden Hearing Loss. Trends Hear. 

2016 Jan-Dec;20:2331216516686768

667. Paakonen (2005) Protection efficiency hearing protectors against military noise from handheld 

weapons and vehicles. Noise and Health 2005;Ê26 (7): 11.

668. Packer, M., et al (2013) Integrated Care for Multisensory Injury. Psychiatr Ann. 2013 

Jul;43(7):334-337

669. Park (2011) aSynuclein Deficiency and Efferent Nerve Degernation in the Mouse Cochlea. 

Neurosci Res. 2011 Nov;71(3):303-10

670. Park (2020) Analysis of Occupational Safety and Health Administration (OSHA) noise standard 

violations over 50 years - 1972 to 2019. Am J Ind Med. 2020 Jul;63(7):616-623

671. Patil (2015) Use Hearing Protection Military Operations. J.R. Army Med Corps 2011; 4 

(157):381-384

672. Patterson (1992) Experimental Basis for the Estimation of Auditory System Hazard Following 

Exposure to Impuse Noise. No. USAARL-92-17. ARMY AEROMEDICAL RESEARCH LAB 

FORT RUCKER AL, 1992.

673. Patterson (2004) Evaluation of an Auditory Hazard Model Using Data from Human Volunteer 

Studies. (No. USAARL-2005-01). ARMY AEROMEDICAL RESEARCH LABÊ

674. Patterson (1994) Actual Effectiveness of Hearing Protection in High Level Impulse Noise. 

USAARL Report No. 94-48ARMY AEROMEDICAL RESEARCH LAB FORT RUCKER AL, 

1994.

675. Patterson (1994) Actual Effectiveness of Hearing Protection in High Level Impulse Noise 

USAARL.pdf. (1994) USAARL Report No. 94-48

676. Patterson, T., et al (2013) Concurrent and Co-Located Early Intervention for Concussion and 

Acute Stress Reaction. Psychiatr Ann. 2013 Jul; 43(7):313-317

677. Paul (2017) Evidence that hidden hearing loss underlies amplitude modulation encoding deficits 

in individuals with and without tinnitus. Hear Res. 2017 Feb;344:170-182

678. Paul (2017) Subcortial Amplitude Modulation Encoding Deficits Suggest Evidence. J Acoust Soc 

Am. 2017 Nov;142(5):EL434

679. Paul (2018) Envelope Following Responses, Noise Exposure, and Evidence of 

Cochlearsynaptopathy in Humans. J Acoust Soc Am. 2018 Jun;143(6):EL487

680. Pedrielli et al.(2008) Just noticeable differences of loudness and sharpness for earth moving 

machines. Presentation at Acoustics ‘08 Paris.

681. Peng (2012) Hearing Aids - The Basic Information You Need to Know. FDA Basics Webinar; 

2012 May

682. Perkins (1979) Occupational Health Priorities for Health Standards: The Current NIOSH 

Approach. Amer. J. of Public Health 1979; 5 (69):444-448

683. Perreau (2019) Establishing a group educational session for hyperacusis patients. Am J Audiol. 

2019 Jun; 28(2):245-250

684. Peters (1994) Hearing Impairment as a Predictor of Cognitive Decline in Dementia. Journal of the 

American Geriatrics Society 1988; 11 (36): 981-986.

685. Peters (1998) Hearing Impairment as a Predictor of Cognitive Decline in Dementia. Journal of the 

American Geriatrics SocietyÊ1988; 11 (36): 981-986.

686. Pfannenstiel (2014) Noise-induced hearing loss - a military perspective. Curr Opin Otolaryngol 

Head Neck Surg. 2014 Oct;22(5):384-7

687. Phillips (2016) Feasibility of a Bilateral 4k-6k Hz Notch as a Phenotype for Genetic Association 

Analysis. Int J Audiol. 2015;54(10):645-652

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 155 of 171
688. Phillips (2019) Noise and Occupational Medicine - Common Practice Problems. J Occup Environ 

Med. 2019 Dec;61(12):1019-1029

689. Photographs of Stryker

690. Photographs of Bradley IFV

691. Plack (2014) Perceptual Consequences of ÒHiddenÓ Hearing Loss. Trends Hear. 2014; 9 (18): 1-

11

692. Plack (2016) Toward a Diagnostic Test for Hidden Hearing Loss. Trends Hear. 2016 Sep 7;20

693. Polumbo (2015) The Management and Outcomes of Pharmacological Treatments for.pdf. (2015) 

Current Neuropharmacology, 13, 692-700

694. Popelka (2020) Moderate Alcohol Consumption and Hearing Loss A Protective Effect.pdf. 

(2000) Journal American Geriatrics Society Vol. 48, No. 10, 1273-1278

695. Pottier (2009) INCIDENCE AND RISK OF COCHLEOTOXICITY AND 

VESTIBULOTOXICITY IN PATIENTS WITH HAEMATOLOGICAL MALIGNANCIES.pdf

696. Prendergast (2017) Effects of noise exposure on young adults with normal audiograms I: 

Electrophysiology. Hear Res. 2017 Feb;344:68-81

697. Price (1992) Importance of Spectrum for Rating Hazard: Theoretical Basis. No. HEL-TM-2-92. 

US ARMY HUMAN ENGINEERING LAB 1992

698. Price (2010) Critique of An Analysis of the Blast Overpressure Study Data Comparing Three 

Exposure Criteria. ARL-CR-657; 2010 Aug

699. Price (2010) Critique of An Analysis of the Blast Overpressure Study Data Comparing Three 

Exposure Criteria by Murphy, Khan, and Shaw. Report Number EPHB 2009

700. Price (2018) The philosophy, theoretical bases, and implementation of the AHAAH model for 

Evaluation of Hazard from exposure to Intense Sounds. ARL-TR-8333 2018 Apr

701. Price (2018) The Philosophy, Theoretical Bases, and Implementation of the AHAAH Model for 

Evaluation of Hazard from Exposure to Intense Sounds. US Army Research Laboratory 2018; 

ARL-TR-8333

702. Pusz (2017) Traumatic hearing loss in the context of blast-related tympanic membrane 

perforation. Mil Med. 2017 Jan;182(1):e1645-e1648

703. Rabinowitz (2000) Noise-induced hearing loss. Am Fam Physician 2000; 61(9): 2749-2756

704. Rabinowitz, Peter M. (2000), ”Noise-Induced Hearing Loss,” American Family Physician, vol. 

61, no. 9, page 2749.

705. Rademaker-Lakhal (2005) Relationship Between Cisplatin Administration and the Development 

of Ototoxicity.pdf. (2006) Journal of Clinical Oncology VOLUME 24, NUMBER 6, Pages 918-

924

706. Radziwon (2019) Noise-Induced Loudness Recruitment and Hyperacusis. 2019 Dec 1;422:212-

227

707. Radziwon (2019) Psychophysical Changes in Temporal Processing in Chinchillas with NIHL. J 

Acoust Soc Am. 2019 Nov;146(5):373

708. Rajguu (2013) Military Aircrew and Noise-Induced Hearing Loss: Prevention and Management. 

Aviat Space Environ Med. 2013; 12 (84): 1268-1276

709. Ramma (2019) Prevention of treatment-induced ototoxicity-An update for clinicians.pdf. (2019) 

SAMJ Vol. 109, No. 3, 145-149

710. Rask (2012) Human Cochlea - anatomical Characteristics and Their Relevance for Cochlear 

Implantation. Anat Rec (Hoboken). 2012 Nov;295(11):1791-811

711. Rauschecker (2010) Tuning out the noise - Limbic-auditory interactions in tinnitus. Neuron. 2010 

Jun 24;66(6):819-26

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 156 of 171
712. Rauschecker (2010) Tuning Out the Noise Limbic-Auditory Interactions in Tinnitus.pdf. (2010) 

Neuron 66

713. Reactions: A Disproportionality Analysis Using the Italian Spontaneous Reporting Database, 

10:1161.

714. Rennie, C. et al (2016) Pneumatic Otoscope Examination. Medscape 2016 Feb

715. Results of the National Institute for Occupational Safety and Health (2009) - U.S. Environmental 

Protection Agency Interlaboratory Comparison of American National Standards Institute 812.6-

1997 Methods A and B. J. Acoust. Soc. Am.. Vol. 125. No. 5. May 2009.

716. Rezaee, M. et al (2011) Assessment of Impulse Noise Level and Acoustic Trauma in Military 

Personnel. Trauma Mon. 2012 Jan;16(4):182-7

717. Rhinological and Otological Society, Laryngoscope, 123:1527Ð1530

718. Ridley (2018) Using Thresholds in Noise to Identify Hidden Hearing Loss in Humans. Ear Hear. 

2018 Sep/Oct;39(5):829-844

719. Rosati (2020) Environmental Exposures and Hearing Loss.pdf. (2020) Int. J. Environ. Res. Public 

Health, 17, 4879

720. Royster (1994) Development of a new standard laboratory protocol for estimating the field 

attenuation of hearing protection devices. Part I. Research of Working Group 11, Accredited 

Standards Committee S12, Noise.. The Journal of the Acoustical Society of AmericaÊ1996; 3 

(99): 1506-1526.

721. Royster (2017) Preventing Noise-Induced Hearing Loss. N C Med J. 2017 Mar-Apr;78(2):113-11

722. Royster et al (1996) Development of a new standard laboratory protocol for estimating the field 

attenuation of hearing protection devices - Part I. J. Acoust. Soc. Am. 1996; 99 (3): 1506-1526

723. Royster JD. et al. (1996) Development of a new standard laboratory protocol for estimating the 

field attenuation of hearing protection devices. Part I. Research of Working Group 11 Accredited 

Standards Committee S12. Noise. J Acoust Soc Am, 99, 1506-1526

724. Ryan, A. et al (2016) Temporary and Permanent Noise-induced Threshold Shifts - A Review of 

Basic and Clinical Observations. Otol Neurotol. 2016 Sep;37(8):e271-5

725. Safety, 5:3, 383-399

726. Sakamoto (2000) Extended high-frequency ototoxicity induced by the first administration of 

cisplatin.pdf. (2000) OtolaryngologyÐHead and Neck Surgery

727. Salvi (2020) Functional Neuroanatomy of Salicylate - and Noise-Induced Tinnitus and 

Hyperacusis. Curr Top Behav Neurosci. 2020 Jul 12

728. Saunders (2009) Hearing loss in veterans and the need for hearing loss prevention programs.. 

Noise Health. 2009 Jan-Mar;11(42):14-21

729. Scharine (2005) An Evaluation of Selected Communications Assemblies and Hearing Protection 

Systems: A Field Study Conducted for the Future Force Warrior Integrated Headgear Integrated 

Process Team. ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD HUMAN 

RESEARCH AND ENGINEERING DIRECTORATE 2005

730. Scharine (2013) Evaluation of Variants of the 3M Peltor ComTAC and Tactical Communication 

and Protection System (TCAPS) Headsets: Measures of Hearing Protection and Auditory 

Performance. Army Research Laboratory 2013;

731. Scharine (2014) U.S. Marine Corps Level-Dependent Hearing Protector Assessment: Objective 

Measures of Hearing Protection Devices. Army Research Laboratory 2014;

732. Scherer (2012) Tinitus Retraining Therapy Trial. Trials 2014; (15) 396

733. Scherer (2019) Effect of Tinnitus Retraining Therapy vs Standard of Care on Tinnitus-Related 

Quality of Life. JAMA Otolaryngol Head Neck Surg. 2019 Jul; 145(7):597-608

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 157 of 171
734. Seist (2020) Regeneration of Cochlear Synapses by Systemic Administration of a 

Bisphosphonate. Front Mol Neurosci. 2020 Jul 14;13:87

735. Sereda (2020) A Process for prioritizing sytematic reviews in tinnitus. Int J Audiol. 2020 

Aug;59(8):640-646

736. Sewell (2004) Hearing loss in union army veterans from 1862 to 1920. The Laryngoscope 

2004;Ê12 (114): 2147-2153.

737. Shargorodsky (2010) Prevelance and Characteristics of Tinnitus among US Adults.pdf. (2010) 

The American Journal of Medicine 123, 711-718

738. Shargorodsky, et al (2010) Prevalence & Characteristics of Tinnitus Among US Adults. Am J 

Med. 2010 Aug;123(8):711-8

739. Sharma (2001) A case of sensorineural deafness following ingestion of Ecstasy.pdf. (2001) The 

Journal of Laryngology & Otology, Vol. 115, pp. 911Ð915

740. Shearer (2019) Auditory Synaptopathy, Auditory Neuropathy, and Cochlear Implantation. 

Laryngoscope Investig Otolaryngol. 2019 Jul 1;4(4):429-440

741. Shearer, A., et al (2017) Hereditary Hearing Loss & Deafness Overview. 1999 Feb 14 [updated 

2017 Jul 27]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, 

Amemiya A, editors. GeneReviews [Internet]. Seattle (WA): University of Washington, Seattle; 

1993Ð2020

742. Sheffield (2015) The relationship between hearing acuity and operational performance in 

dismounted combat. Proceedings of the Human Factors and Ergonomics Society 2015: 1346-

1350

743. Sheffield (2016) The Effects of Hearing Impairment on Fire Team Performance in Dismounted 

Combat. Proceedings of the Human Factors and Ergonomics Society Annual Mtg. Sage 

Publications 2016; 1 (60): 1509-1513

744. Sherlock & Eisebnan (2020) Current Device-based Clinical Treatments for Tinnitus. Otolaryngol 

Clin North Am. 2020 Aug;53(4):627-636

745. Shi, L. et al (2016) Cochlear Synaptopathy and Noise-Induced Hidden Hearing Loss. Neural 

Plast. 2016; 2016:6143164

746. Shore (2016) Maladaptive Plasticity in Tinnitus - Triggers, Mechanisms and Treatment. Nat Rev 

Neurol. 2016 Mar;12(3):150-60

747. Shore, S. & Wu, C. (2019) Mechanisms of noise-induced tinnitus - Insights from cellular studies. 

Neuron. 2019 Jul;103(1):8-20

748. Shore, S., & Wu, C. (2019) Mechanisms of noise-induced tinnitus - Insights from cellular studies. 

Neuron. 2019 Jul; 103(1):8-20

749. Si (2020) Productivity Burden of Occupational Noise-Induced Hearing Loss in Australia - A Life 

Table Modeling Study. Int J Environ Res Public Health. 2020 Jun 29;17(13):4667

750. Silencer Central. Relative Sound Pressure Levels in Decibels (dB). Silencecentral.com 

751. Silva (2020) Is Noise-Induced Hearing Loss Still a Public Health Problem After Decades of 

Legislation. Braz J Otorhinolaryngol. 2020 Apr 10: S1808-8694(20)30036-7

752. Sindhusake, D., et al (2004) Factors Predicting Severity of Tinnitus: A Population-Based 

Assessment. J Am Acad Audiol. 2004 Apr;15(4):269-80

753. Singh, S. & Kapoor, N. (2014) Health Implications of Electromagnetic Fields, Mechanisms of 

Action & Research Needs. Advances in Biology 2014 Jan;(2014):1-25

754. Smalt (2017) Noise dosimetry for tactical environments. Hear Res. 2017 Jun; 349:42-5

755. Smalt (2019) The Effect of Hearing-Protection Devices on Auditory Situational Awareness and 

Listening Effort.pdf. (2019) EAR & HEARING, VOL. XX, NO. XX, 00Ð00

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 158 of 171
756. Smith (2003) Selected Topics in Deployment Occupational Medicine. 2003 Military Preventive 

Medicine: Mobilization and DeploymentÊ1.

757. Smith (2011) Can You Hear Me Now: The leading army injury and disability. USAWC Strategy 

Research Project 2011 Mar

758. Smith (2011) Development of the Self-Efficacy for Tinnitus Management Questionnaire. J Am 

Acad Audiol. 2011 Jul-Aug;22(7):424-40

759. Smoorenburg GF. (1996) Assessment of hearing protector performance in impulsive noise. Final 

report (report TM-96-CO42). Soesterberg, Netherlands: TNO. Human Factors Research Inst.;

760. Smoorenburg GF. Assessment of hearing protector performance in impulsive noise. Final report 

(report TM-96-CO42). Soesterberg, Netherlands: TNO.

761. Soderlund (2011) Prevalence of permanent threshold shifts in the United States air force hearing 

conservation program by career field, 2005-2011. J Occup Environ Hyg. 2016;13(5):383-92

762. Somma (2008) Extended High-frequency Audiometry and Noise Induced Hearing Loss in 

Cement Workers. Am J Ind Med. 2008 Jun;51(6):452-62

763. Song (2016) Coding Deficits in Hidden Hearing Loss Induced by Noise - The Nature and 

Impacts. Sci Rep. 2016 Apr 27; 6:25200

764. Soundscape (2005) Journal of Acoustic Ecology Vol 6 No. 1. Journal of Acoustic Ecology 2005; 

1 (6)

765. Soylemez (2020) Dual-Task Performance and Vestibular Functions in Individuals with Noise 

Induced Hearing Loss. Am J Otolaryngol. 2020 Aug 11;41(6):102665

766. Spankovich (20xx) Tinnitus and Sensitivity 17.1 Definition and Epidemiology of Tinnitus.pdf

767. Spankovich (20xx) theearcourse.pdf

768. Spankovich (2008) Programs, regulations & implementation. PPT.pdf

769. Spankovich (2008) Tinnitus _ Normal Hearing PPT.pdf

770. Spankovich (2012) Anatomy and Physiology of the Auditory System PPT.pdf

771. Spankovich (2012) Introduction to Acoustics and Psychoacoustics PPT.pdf

772. Spankovich (2012) Introduction to Audiometry PPT.pdf

773. Spankovich (2012) The basic science of audiological diagnostics PPT.pdf

774. Spankovich (2013) Hearing disorders Noise induced hearing loss PPT.pdf

775. Spankovich (2014) Healthy Diets, Healthy Hearing National Health and Nutrition Examination 

Survey, 1999Ð2002.pdf

776. Spankovich (2014) Lecture 3 SNHL I and Clinical Decision Making PPT.pdf

777. Spankovich (2015) CAA_SyanptopathyNoise.pdf

778. Spankovich (2015) Nutrition + Lifestyle Roles in Risk Modification for Hearing Loss and 

Tinnitus PPT.pdf

779. Spankovich (2015) Translational Research in Hidden Hearing Loss OleMiss_Talk PPT.pdf

780. Spankovich (2016) Tinnitus Management Approaches PPT.pdf

781. Spankovich (2017) Relationship between dietary quality, tinnitus and hearing level- data from the 

national health and nutrition examination survey.pdf

782. Spankovich (2018) Self-reported hearing difficulty tinnitus and normal audiometric thresholds, 

The national health and nutrition examination survey 1999-2002. Hear Res. 2018 Feb; 358:30-36

783. Spankovich (2018) Ototoxicity Monitoring PPT.pdf

784. Spankovich (2019) Hearing Testing-PPT.pdf

785. Spankovich (2019) Signia Tinnitus Evaluation and Management Workshop PPT.pdf

786. Spankovich, C. et al (2014) Temporary threshold shift after impulse-noise during video game 

play - Laboratory data. Int J Audiol. 2014 Mar;53 Suppl 2(0 2): S53-65

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 159 of 171
787. Spoor (2018) OTC hearing aids may stimulate demand for audiology services. The Hearing 

Journal 2018 Oct; 10(71):6

788. Staab (2014) The Human Ear Canal. https://hearinghealthmatters.org/waynesworld/2014/humanear-canal-v/

789. Stephenson (2010) Perspectives on Efficacy of the U.S. Army policy on hearing conservation 

programs. Mil Med. 2010 Jan;175(1): xii-xvi

790. Sulkowski (2017) Contemporary noise-induced hearing loss prevention. Otolaryngol Pol. 2017 

Aug 31;71(4):1-7

791. Suresh & Krishnan (2020) Search for Electrophysiological Indices of Hidden Hearing Loss in 

Humans. Ear Hear. 2020 Jul 13.

792. Suter (1978) The Ability of Mildly Hearing-impaired Individuals to Discriminate Speech. 

EPA/USAF 1978

793. Swan (2017) Prevalence of Hearing Loss and Tinnitus in Iraq and Afghanistan Veterans: A 

chronic effect of neurotrama consortium study. Hear Res. 2017 Jun; 349:4-12

794. Swan (2017) Prevalence of Hearing Loss and Tinnitus. Hear Res. 2017 Jun; 349:4-12

795. Swayne (2015) Noise Attenuation Performance. Air Force Research Laboratory 2015;

796. Takada (2019) Training in the proper use of earplugs - an objective evaluation. Work. 

2020;65(2):401-407

797. Takihata (2020) The Influence of a Noise Environment on Hearing Impairment and Tinnitus. 

Auris Nasus Larynx. 2020 Jun 8: S0385-8146(20)30128-0

798. Talcott (2012) Azimuthal Auditory localization of gunshots in a realistic field environment: 

Effects of open-ear versus hearing protection-enhancement devices (HPEDs_, military vehicle 

noise, and hearing impairment. Int J Audiol. 2012 Feb;51 Suppl 1: S20-30

799. Tambs (2006) Hearing Loss Induced by Occupational and Impulse Noise: Results on threshold 

shifts by frequencies, age and gender from the Nord-Trandelag Hearing Loss Study. Int J Audiol. 

2006 May;45(5):309-17

800. Tambs, K., (2004) Moderate Effects of Hearing Loss on Mental Health and Subjective WellBeing - Results from the Nord-Trodelag Hearing Loss Study. Psychosom Med. 2004 SepOct;66(5):776-82

801. Tanaka (2009) The effects of acoustic environment after traumatic noise exposure on hearing and 

outer hair cells. Hear Res. 2009 Apr;250(1-2):10-8

802. Technical Report

803. Tepe (2017) Hidden Hearing Injury - The Emerging Science and Military Relevance of Cochlear 

Synaptopathy. Mil Med. 2017 Sep;182(9): e1785-e1795

804. Tepe, V., et al (2013) Polytraumatic TBI - Perspectives from Military Medicine. Psychiatr Ann 

2013 Jul;43(7):308-312

805. TG250, Army Readiness through Hearing Loss Prevention (2014) US Army Public Health 

Command, July

806. Thakur (2013) Hearing Loss With Phosphodiesterase 5 Inhibitors A Prospective and Objective 

Analysis With Tadalafil.pdf. (2013) The American Laryngological,

807. The Journal of Acoustical Society of America. (2014) The Journal of the Acoustical Society of 

America 2014; 4 (136):

808. Theodoroff (2015) Hearing Impairment and Tinnitus: Prevalence, Risk Factors, and Outcomes in 

US Service Members and Veterans Deployed to the Iraq and Afghanistan Wars. Epidemiol Rev. 

2015; (37): 71-85

809. Theodoroff and Konrad-Martin (2020) Abstract Acoustic Trauma and Tinnitus, the US Military 

Experience. Otolaryngol Clin North Am. 2020 Aug;53(4):543-553

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 160 of 171
810. Theodoroff, S. et al (2019) Decreased sound tolerance associated with blast exposure. Sci Rep. 

2019 Jul 15;9(1):10204

811. Tikka (2020) Cochrane Method for Systematic Review and Meta-Analysis of Int. to Prevent 

Occupational NIHL. Codas. 2020 Apr3;32(2):e20190127

812. Tikka, C. et al (2017) Interventions to prevent occupational noise-induced hearing loss (Review). 

Cochrane Database Syst Rev. 2017 Jul 7;7(7)

813. to real-world environments. J Acoust Soc Am. 2019 Nov;146(5):3646

814. Tran (2012) User Evaluation of a Bone Conduction Communication Headset During the Patriot 

2007 Joint Field Training Exercise. ARL-TR-5973; 2012 Apr

815. TTRTTRG (2019) Effect of Tinnitus Retraining Therapy vs Standard of Care on Tinnitus-Related 

Quality of Life A Randomized Clinical Trial.pdf. (2019) JAMAOtolaryngologyÐHead & Neck 

Surgery

816. Tu (2014) Anthropometry External Auditory Canal by Non-contactable Measurement. Appl 

Ergon. 2015; (50): 50-55

817. Tuepker (2018) A qualitative study of implementations and adaptations to Progressive Tinnitus 

Management (PTM) delivery. PLoS One. 2018 May;13(5):e0196105

818. Tufts (2003) Speech production in noise with and without hearing protection. The Journal of the 

Acoustical Society of America 2003; 2 (114): 1069-1080.

819. Tufts (2007) NSMRL TECHNICAL REPORT# 1247 MODEL FOR ESTIMATING NOISEINDUCED HEARING LOSS.pdf

820. Tufts, J. et al (2009) Auditory Fitness for Duty - A Review. J Am Acad Audiol. 2009 

Oct;20(9):539-57.

821. Tunkel, D et al (2014) Clinical Practice Guideline - Tinnitus Executive Summary. Otolaryngol 

Head Neck Surg. 2014 Oct;151(4):533-41

822. Turkdogru (2013) Validity point source assumption of a Rotor for Farfield Acoustic 

Measurements with Shielding. Georgia Institue of Technology 2010

823. Tyson, A., (2003). New Army ‘Stryker’ Combat Vehicle Nears Iraq Test. The Christian Science 

Monitor

824. Udupi, V. et al (2013) The relationship of perceived severity of tinnitus with depression, anxiety, 

hearing status, age & gender in individuals with tinnitus. Int Tinnitus J. 2013;18(1):29-34

825. Unknown (xxxx) Corrections to Nominal NRR's.pdf

826. US Army (2006) Personal Hearing Protective Devices Their Fitting, Care, and Use. TG41, Feb 

2006

827. US Army (2020) TG-351A Health Hazard Assessor's Guide

828. United States Army (2005). Stryker. US Army Weapons Systems Handbook. 

829. US DOJ (1973) Hearing Protectors for Use on Firing Ranges

830. US EPA (1979) Product Noise Labeling Requirements. US EPA 1979; EPA 550/9-79-256

831. USACHPPM (2001) Hearing Protection Devices dual ended tested by DOD

832. USAPHC (2012) Criteria and Procedures for Auditory Health Hazard Assessment of Impulse 

Noise (Blast Over Pressure). U.S. Army Public Health Command 2012;

833. USACHPPM. Noise Levels of Common Army Equipment. 

834. USAPHC xxxx Tinnitus Fact Sheet 51-3-713. USPHC; FACT SHEET 51-003-0713

835. USAPHC xxxxx Hearing Loss Fact Sheet 51-1-713. USPHC; FACT SHEET 51-001-0713

836. Valderrama (2016) Effects of lifetime noise exposure on the middle-age human auditory 

brainstem response, tinnitus and speech-in-noise intelligibility.pdf. (2018) Hearing Research 365

36-48

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 161 of 171
837. Vannson (2015) Quality of Life and Auditory Performance in Adults with Asymmetric Hearing 

Loss. Audiol Neurootol. 2015;20 Suppl 1:38-43

838. Varela-Nieto (2020) Drug development for noise-induced hearing loss. Expert Opin Drug Discov. 

2020 Aug 25:1-15

839. Various E-mails to and from Kevin Michael. 3M_MDL000024363-3M_MDL000024693

840. Vermiglio (2012) The Relationship between high-frequency pure-tone hearing loss, hearing in 

noise test (HINT) thresholds, and the articulation index. J Am Acad Audiol 2012; (10):779-88

841. Vermiglio (2018) Argument self-report reference standard audiology. J Am Acad Audiol. 2018 

Mar; 29(3):206-222

842. Vernon, J. & Meikle, M. (2003) Masking devices & alprazolam treatment for tinnitus. 

Otolaryngol Clin North Am. 2003 Apr;36(2):307-20

843. Viallet (2016) Investigation of the variability in earplugs sound attenuation measurements using a 

finite element model. Applied Acoust. 2015 Mar; 89:333-344

844. Viallet (2016) Investigation of the variability in earplugs sound attenuation measurements using a 

finite element model

845. Viana, L. et al (2016) Cochlear neuropathy in human presbycusis - confocal analysis of hidden 

hearing loss in post-mortem tissue. Hear Res. 2015 Sep; 327:78-88

846. Viasitsa (2013) Screen of FDA-approved drug library reveals compounds that.pdf. (2012) Hear 

Res.; 294(0): 153:165

847. Vick, A., et al., (2002). The Stryker Brigade Combat Team: Rethinking Strategic Responsiveness 

and Assessing Deployment Options.

848. Von Gierke, H. (1955) Criteria for Short Time Exposures to High Intensity Jet Aircraft Noise.

849. Von Gierke, H. (1957) Criteria for Work Spaces, Living Spaces, and Other Airbase Areas.

850. Wall, A. et al (2019) Cumulative noise exposure model for outdoor shooting ranges. J Acoust Soc 

Am. 2019 Nov;146(5):3863

851. Wang (2019) Presbycusis- An Update on Cochlear Mechanisms and Therapies.pdf. (2019) 

Journal of Clinical Medicine Vol. 9, No 18

852. Wang (2020) Auditory Neural Plasticity in Tinnitus Mechanisms and Management. Neural Plast. 

2020 Jul 1; 2020:7438461

853. Warner (2015) Jet Fuel, Noise, and the Central Auditory Nervous System - A Literature Review. 

Military medicine 2015: 9 (180): 950-955

854. Warner, R. et al (2015) Jet Fuel, Noise and Central Auditory Nervous System - A Literature 

Review. Mil Med. 2015 Sep;180(9):950-5

855. Watts (2018) Development of the Warfighters Hearing Health Instructional Primer App. Mil 

Med. 2018 Mar;183(suppl_1):231-236

856. Weatherless (2007) Effects of the Advanced Combat Helmet (ACH) and Selected 

Communication and Hearing Protection Systems (C&HPSs) on Speech Communication: TalkThrough Systems. ARL 2007 April

857. Weatherless (2015) Effects of the Advanced Combat Helmet (ACH) and Selected 

Communication and Hearing Protection Systems (C&HPSs) on Speech Communication. Army 

Research Lab 2007; ARL-TR-4078

858. Weber, D., et al (2013) Three-dimensional Reproducibility of Natural Head Position. Am J 

Orthod Dentofacial Orthop. 2013 May;143(5):738-44

859. Wei (2020) RNA-seq Profiling and Co-Expression Network Analysis of Long Noncoding RNAs 

and mRNAs.... Neuroscience. 2020 May 10; 434:120-135

860. Weisz (2006) High-frequency tinnitus without hearing loss does not mean absence of 

differentiation. Hear Res. 2006 Dec;222(1-2):108-14

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 162 of 171
861. Wells (2013) Attenuation characteristics fit-compromised earmuffs and various non-standard 

hearing protectors. Proc. Meet. Acoust. 2013; 1 (19):

862. Wells (2015) Hearing loss associated with military combat deployment. Noise Health. 2015 JanFeb;17(74):34-42

863. Whitlon, D. (2017) Drug discovery for hearing loss - Phenotypic screening of chemical 

compounds on primary cultures of the spiral ganglion. Hear Res. 2017 Jun; 349:177-181

864. WHO (2015) Hearing loss due to recreational exposure to loud sounds. WHO. 2015 NLM WV 

270

865. Wiener and Keast, "Experimental Study of the Propagation of Sound Over Ground," Journal of 

the Acoustical Society of America, 31, p. 724.

866. Williams (2014) Assessment of Four Passive Hearing Protection Devices for Continuous Noise 

Attenuation, Impulsive Noise Insertion Loss, and Auditory Localization Performance. USAARL 

2014

867. Williams (2014) USAARL Assessment of Four Passive Hearing Protection Devices for 

Continuous Noise Attenuation, Impulsive Noise Insertion Loss. Army Aeromedical Research Lab 

2014; USAARL-2015-01

868. Wilson, R. & McArdle, R. (2013) Characteristics of the audiometric 4,000 Hz notch (744,553 

veterans) and the 3,000, 1,000 and 6,000 Hz notches (539,932 veterans). J Rehabil Res Dev. 

2013;50(1):111-32

869. Wojtczak (2017) Weak Middle-Ear Muscle Reflex in Humans with Noise-Induced Tinnitus and 

Normal Hearing. eNeuro. 2017 Nov 27;4(6): ENEURO.0363-17.2017

870. Wolgemuth (1994) The Effectiveness of the Navy's Hearing Conservation Program. Military 

Medicine 1995; 5 (160): 219-222

871. Wu (2020) Age-related hearing loss is dominated by damage to inner ear sensory cells, not the 

cellular battery that powers them.pdf. (2020) Journal of Neuroscience; 

10.1523/JNEUROSCI.0937-20.2020

872. Wu (2020) Noise-Induced Loss of Sensory Hair Cells is Mediated by ROS AMPKa Pathway. 

Redox Biol. 2020 Jan; 29:101406

873. Xie (2012) New developments in aminoglycoside therapy and ototoxicity.pdf. (2011) Hear Res.; 

281(1-2): 28Ð37

874. Xiong (2019) Missed Hearing Loss in Tinnitus Patients with Normal Audiograms. Hear Res. 

2019 Dec; 384:107826

875. Xiping, Z. (2019) Disrupted nerve cell function and Tinnitus-Related Quality of Life: A 

Randomized Clinical Trial. Hear Hlth. 2019:36

876. Yankaskas (2011) Noise Control on Ships- Enabling Technologies. American Society of Naval 

Engineers 2011 May

877. Yankaskas (2012) Noise-induced tinnitus and hearing loss in the military. Hear Res 2013;(295):3-

8

878. Yankaskas (2012) Prelude - Noise-induced tinnitus and hearing loss in the military. Hear Res. 

2013 Jan; 295:3-8

879. Yankaskas (2013) Acoustal Engineering Controls and Estimated Return on Investment for DoD 

Selected High Noise Sources: A Roadmap for Future Noise Control in Acquisition. DOD 2013;

880. Yankaskas (2017) Auditory injury-- A military perspective. Hear Res. 2017 Jun; 349:1-3

881. Yankaskas (2017) Editorial: Auditory injury - A military perspective. Hear Res. 2017 Jun; 349:1-

3

882. Yankaskas (2017) Engineering Out the Noise. Hear Res. 2017 Jun; 349:37-41

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 163 of 171
883. Yankaskas, K., et al (2017) Editorial - Auditory injury -- A military perspective. Hear Res. 2017 

Jun; 349:1-3

884. Yates, C., et al (2010) Fatal Case of Tumor-Associated Hemorrhage in a Large Vestibular 

Schwannoma. Ann Otol Rhinol Laryngol. 2010 Jun;119(6):402-5

885. Yehudai (2017) Acute Acoustic Trauma Among Soldiers during an Intense Combat. J Am Acad 

Audiol. 2017 May;28(5):436-443

886. Yong (2015) Impact of noise on hearing in the military. Mil Med Res. 2015 Feb 25; 2:6

887. Yorgason (2006) Understanding drug ototoxicity- molecular insightsfor prevention and clinical 

management.pdf. (2006) Understanding drug ototoxicity: molecular insights for prevention and 

clinical management, Expert Opinion on Drug

888. Yorgason (2010) Acetaminophen ototoxicity after acetaminophen hydrocodone abuse Evidence 

from two parallel in vitro mouse models.pdf. (2010) OtolaryngologyÐHead and Neck Surgery 

142, 814-819

889. Young (2015) Impact of Noise on Hearing in the Military. Mil Med Res. 2015 Feb 25; 2:6

890. Yu (2015) Anthropometry of external auditory canal by non-contactable measurement. Applied 

Ergonomics 2015; 50: 50-55

891. Yucel (2018) Effect of statins on hearing function and subjective tinnitus.pdf. (2019) ROM. J. 

INTERN. MED., 57, 2, 133Ð140

892. Yueh, B, et al (2010) Long-Term Effectiveness of Screening for Hearing Loss - The Screening 

for Auditory Impairment Which Hearing Assessment Test (SAI-WHAT) Randomized Trial. J Am 

Geriatr Soc. 2010 Mar;58(3):427-34

893. Zagadou (2016) An Interim LAeq8 Criterion for Impulse Noise Injury. Military Med 2016; 

181(5): 51-58

894. Zemlin (1968) Ear Anatomy Section. Prentice-Hall 1968

895. Zhang (2020) New insights on repeated acoustic injury. Hear Res. 2020 Aug; 393:107996

896. Zhang (2020) New Metrics Needed in the Evaluation of Hearing Hazard Associated with

Industrial Noise Exposure. Ear Hear. 2020 Aug 19

897. Zheng (2017) Cochlear hair cell regeneration after noise-induced hearing Loss: Does regeneration 

follow development? Hear Res. 2017 Jun; 349:182-196

898. Zhou (2020) Socio-economic disparity in the global burden of occupational noise-induced 

hearing loss. Occup Environ Med. 2020 Aug 24:

899. Zimpfer (2014) Impact of Hearing Protection Devices on Sound Localization Performance. 

Frontiers in Neuroscience 2014; 8(135): 1-10

900. “Personal protective equipment” (2019), APHC, 

https://phc.amedd.army.mil/topics/workplacehealth/ih/Pages/Personal-ProtectiveEquipment.aspx.

901. AR 40-501. Standards of Medical Fitness, Army Regulation. 2007

902. Army Hearing Program - Europe AER 40-501. Army Regulation in Europe 40-501. 2018

903. Army Occupational Health Program Aberdeen Proving Ground, MD21010. Army Environmental 

Hygiene Agency Aberdeen. 1978: 1-2f5

904. Army Hearing Program (DAP 40-501). 2015.

905. Aearo CAEv1 and CAEv2 Brochure (Colored). 2005.

906. 3M CAEv2 Brochure (Colored). 2010

907. Berger, E. (2012) Evaluation of the Surefire EP4 Sonic Defenders Plug. EAR 12-03/HP

908. 3M Combat Arms 4.1 Ear Plugs Video - Overview. 2015

909. Binseel (2011) Three Variants of the Dual Mode Combat Arms Earplug. ARL. Poster 

Presentation.

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 164 of 171
910. Air Force Email Thread re CAEv2 Verified Not in Use. 2019. DOD Touhy Document

911. U.S. Army Garrison Hawaii Article - ''Service Members Should File Claims about Faulty Combat 

Arms Earplugs with Private Counsel''. 2019. 3M_MDL000259866-3M_MDL000259918

912. McKinley (2014). Measuring effective detection and localization performance of hearing 

protection devices. AFRL Presentation.

913. ASQ.ANSI Z1.4-2003. Sampling Procedures and Tables for Inspection by Attributes.

914. Dec. 29, 2020 Ltr from Dept. of Defense in Response to Touhy Requests re: HHA noise data of 

M1126 Stryker Vehicle.

915. Dept. of the Army (2019) Fort Leonard Wood Regulation 40-7

916. Steady State Exposures – Priority Health Hazard Assessment

. 

Other Documents Considered: 

a) Deposition Transcript of Annette Childress 30(b)(6) – 9/23/20 and All Exhibits

b) Deposition Transcript of Robert Klun – 06/24/20 and All Exhibits

c) Deposition Transcript of Robert Zielinski – 06/22/20 and All Exhibits

d) Deposition Transcript of Ronald Kieper – 12/20/19 and All Exhibits

e) Deposition transcript of Stephen Todor – 08/24/20 and All Exhibits

f) Deposition Transcript of Brian Hobbs – 06/16/2020 and All Exhibits

g) Deposition Transcript of Richard Price – 08/26/20 and All Exhibits

h) Deposition Transcript of Kathy Gates – 05/29/2020 and All Exhibits

i) Deposition Transcript of Elliott Berger – 09/25/2020 and All Exhibits

j) Deposition Transcript of Elliott Berger – 12/12/2019 and All Exhibits

k) Deposition Transcript of Elliott Berger – 11/13/2019 and All Exhibits

l) Deposition Transcript of Elliott Berger – 12/10/2019 and All Exhibits

m) Deposition Transcript of Elliott Berger – 12/11/2019 and All Exhibit

n) Deposition Transcript of Ron Kieper – 12/20/2019 and All Exhibit

o) Deposition Transcript of Ron Kieper – 12/19/2020 and All Exhibits

p) Deposition Transcript of Robert Falco - 2/12/2020 and All Exhibits

q) Deposition Transcript of Robert Falco - 2/11/2020 and All Exhibits

r) Deposition Transcript of Marc Doty - 7/28/2020 and All Exhibits

s) Deposition Transcript of Dick Knauer - 12/17/2019 and All Exhibits

t) Deposition Transcript of Cyd Kladden - 1/31/2020 and All Exhibits 

u) Deposition Transcript of Robert Zielinski - 6/22/2020 and All Exhibits

v) Deposition Transcript of Kara Cave – 3/11/2021 and All Exhibits

a) Expert Reports of Eric Rose – 10/09/2020

b) Expert Report of Allie Coetzee – 10/09/2020

c) Expert Report of David Madigan – 10/09/2020

d) Expert Report of Timothy Edens – 10/09/2020

e) Expert Report of John Franks – 10/09/2020

f) Expert Report of Blaine Huston – 10/09/2020

g) Expert Report of Roger Juneau – 10/09/2020

h) Expert Report of Chris Marshall – 10/09/2020

i) Expert Report of Mark Packer – 10/09/2020

j) Expert Report of Eric Rose – 10/09/2020

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 165 of 171
k) Expert Report of Vernon Rose – 10/09/2020

l) Expert Report of Christopher Spankovich – 10/09/2020

m) Expert Reports of Dave Eddins – 10/09/2020

n) Rebuttal Report of Dave Eddins – 11/19/2020

o) Expert Report of Steve Armstrong – 10/09/2020

p) Rebuttal Report of Steve Armstrong – 11/19/2020

3M_MDL000002017

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3M_MDL000017328

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3M_MDL000020030

3M_MDL000360414

3M_MDL000756149

3M_MDL000327038

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3M_MDL000535898

3M_MDL000534754

3M_MDL000534753

3M_MDL000534749

FALLONSDT000542

MICHAELASSOC_483

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3M_MDL000028370

3M_MDL000423338

3M_MDL000439465

3M_MDL000434812

3M_MDL000534630

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3M_MDL000332090

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3M_MDL000321796

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3M_MDL000755095

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3M_MDL000533349

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3M_MDL000605908

3M_MDL000607004

3M_MDL000010416

3M_MDL000008420

3M_MDL000010738

FALLON00294

3M_MDL000257999

3M_MDL000627115

3M_MDL000253945

3M_MDL000578447

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3M_MDL000010393

3M_MDL000184852

3M_MDL000619485

3M_MDL000293781

3M_MDL000373403

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3M_MDL000358014

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3M_MDL000499202

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3M_MDL000716257

3M_MDL000392992

3M_MDL000340724

3M_MDL000612663

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3M_MDL000321264

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3M_MDL000692589

3M_MDL000684508

3M_MDL000825746

3M_MDL000527397

3M_MDL000716954

3M_MDL000153471

3M_MDL000005379

3M_MDL000234368

3M_MDL000569995

3M_MDL000258589

3M_MDL000257805

3M_MDL000313390

3M_MDL000581654

3M_MDL000332845

3M_MDL000434769

3M_MDL000724411

3M_MDL000010140

3M_MDL000002024

3M_MDL000008624

3M_MDL000016445

3M_MDL000004550

3M_MDL000258044

3M_MDL000434795

3M_MDL000832501

3M_MDL000599900

3M_MDL000364204

US Attorney’s Office, 2018. District of South Carolina. 3M Company Agrees to Pay $9.1 Million.

U.S. Patent No. 4,867,149. 1989

Blast Effects on Hearing Protectors Video 

US DOD (1998) Instruction Number 6055.1

Email from Whitney to Gear regarding Removing CAEv2 from inventory. 2020. DOD Touhy Production 

Document

Memo for Removal of CAEv2. 2019. DOD Touhy Production Document

AFRL Hearing Protector Evaluation Report - Closed End. 2012. DOD Touhy Production Document 

AFRL Hearing Protector Evaluation Report - Closed End. 2007. DOD Touhy Production Document 

AFRL Hearing Protector Evaluation Report - Open End. 2007. DOD Touhy Production Document

215508 HPDA Report Screenshot

215516 HPDA Report Screenshot

215007 HPDA Report Screenshot

215511 HPDA Report Screenshot

215515 HPDA Report Screenshot

258A06 HPDA Report Screenshot

215012 HPDA Report Screenshot

ARL PPT - Sound Localization with the Combat Arms Earplug. DOD Touhy Production Document

CID Investigation Report (Unredacted) DOD Touhy Production Document

DoD Hearing Conservation Mtg Agenda with Garinther-ISL Notes DOD Touhy Production Document

Medical Procurement Item Description (MPID) #1. 2003. DOD Touhy Production Document

Evaluated Passive Hearing Protection Devices Poster. Hearing Center of Excellence

ISO 9001: 1994

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 170 of 171
Weber's Law of Just Noticeable Difference, University of South Dakota: Available at: 

http://apps.usd.edu/coglab/WebersLaw.html

https://www.dau.edu/cop/esoh/SitePages/About.aspx

https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-E-A-Rflex-Hearing-Protector-withUltraFit-Tips-350-1100-100-EA-Case/?N=5002385+3294755211&rt=rud)

https://phc.amedd.army.mil/topics/workplacehealth/hrc/Pages/default.aspx

Development of the Combat Arms Earplug, Versions 1-4 (V2.4)

Federal Register, vol. 81, no. 63. (2016). Notices: Committee for Purchase from People who are Blind or 

Severely Disabled

Department of the Air Force Memorandum for 43EX. DOD Touhy Production Document.

Case 7:20-cv-02945-MCR-HTC Document 20-6 Filed 08/09/22 Page 171 of 171