Blast-exposed Veterans With Auditory Complaints
Phase: NA
Conditions: Hearing Impairment, Hearing Aid Fitting
Sponsor: VA Office of Research and Development

 
 
 
 
 
 
 
 
 
 
Blast-exposed Veterans with Auditory Complaints, NCT02122458 
Funding Agency: VA ORD, RR&D 
Principal Investigator/Study Chair: Sheila R. Pratt, Ph.D. 
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Abstract 
 
Clinical audiologists at the VA Pittsburgh Healthcare System (VAPHS) have observed a 
substantive increase in the number of veteran’s presenting with self-reported hearing 
problems but who demonstrate normal or near normal hearing sensitivity when tested 
with a standard audiometric test battery. The primary complaint of these veterans is 
difficulty hearing speech in background noise, and preliminary clinical data have 
suggested poor performance on some tests of central auditory processing. Moreover, 
when fitted with mild-gain open-fit hearing aids, which amplify the high-frequency part of 
the speech spectrum, these patients have reported a reduction in their hearing-related 
problems. Nearly all of these veterans have reported histories of blast exposure and 
concussion while Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) 
deployed and described symptoms consistent with post-concussive syndrome. Similar 
auditory patterns for veterans with mTBI have been reported by clinical audiologists 
from other VA medical centers and military facilities although the auditory problems of 
this group of veterans have not been well described or studied (Fausti et al., 2009; Lew 
et al., 2007).  
 
This study was developed in response to the clinical complaints offered by these 
veterans, with the goal being to better understand their problems by extensively 
assessing their auditory and auditory-related characteristics. A group of veterans with 
histories of blast exposure, histories consistent with mTBI, and normal audiometric 
results, but notable auditory complaints will be evaluated with a standard audiometric 
test battery, health status and quality of life questionnaires, auditory physiological test 
procedures, and behavioral central auditory processing tests. We also will administer 
speech perception and psychoacoustic tasks, and verbal working memory and 
language processing tests to better understand various aspects of their ability to hear, 
remember, and process speech and language through audition. A reading test that 
parallels an auditory language-processing task also will be administered to determine if 
any identified language processing problems are limited to the auditory system. 
Comparisons will be made to a control group of veterans who are negative for auditory 
and brain impairments, as well as to a group of veterans with Post Traumatic Stress 
Disorder (PTSD) but without histories of blast exposure or brain injury. In addition, the 
influences of coexisting PTSD will be examined. Secondarily, the benefit of fitting this 
population of veterans with mild-gain hearing aids that amplify the high-frequency part 
of the speech spectrum will be tested.  
 
The information obtained from this study will be a first step in elucidating the problems 
of these veterans and will lay the groundwork for future studies that will focus on 
specific deficit mechanisms. This study also should contribute to the development of an 
effective assessment battery and interventions for this population. 
 
 

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List of Abbreviations 
ABR – Auditory Brainstem Response 
ANOVA – Analysis of Variance 
ANCOVA – Analysis of Covariance 
APHAB – Abbreviated Profile of Hearing Aid Benefit 
BSI-18 – Brief Symptom Inventory – 18 Item 
BTBIS – The Brief Traumatic Brain Injury Screen 
CCT – California Consonant Test 
CRTT – Computerized Revised Token Test 
CRTT-R – Computerized Revised Token Test – Reading 
CRTT-R-Stroop – Computerized Revised Token Test – Stroop 
CT – Computed Tomography 
CPRS – Computerized Patient Record System  
DDT – Dichotic Digits Test 
DoD – Department of Defense 
dB – Decibel 
DPOAE – Distortion Product Otoacoustic Emissions 
FPTC – Fast Psychophysical Tuning Curves 
GIN – Gaps in Noise 
HHIA – Hearing Handicap Inventory for Adults 
HHIE- SO – Hearing Handicap Inventory for Adults – Significant Others 
HL – Hearing Level 
Hz – Hertz 
IOI-HA – International Outcome Inventory – Hearing Aids 
IRB – Internal Review Board 
LDL – Loudness Discomfort Level 
LLR – Long Latency Response 
LiSN-S - Listening in Spatialized Noise – Sentence Test  
M – Mean 
MVPT-4 – Motor-Free Visual Perception Test, version 4 
MLD – Masking Level Difference 
MLR – Middle Latency Response 
MRI – Magnetic Resonance Imaging 
mTBI – Mild Traumatic Head Injury 
NCRAR – National Center for Rehabilitative Auditory Research 
NU-6 – Northwestern University # 6 
OEF/OIF – Operation Enduring Freedom/Operation Iraqi Freedom 
OIO-HA – International Outcome Inventory-Hearing Aids 
PCL-M – PTSD Checklist-Military 
PTSD – Post Traumatic Stress Disorder 
PVAMC – Portland VA Medical Center 
SCAN-3A – SCAN-3: A Test for Auditory Processing Disorders in Adolescents and 
Adults 
SD – Standard Deviation 
SPL – Sound Pressure Level 
SSQ - The Speech Spatial Qualities of Hearing Scale 

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SSW – Staggered Spondaic Word Test 
SWLS – Satisfaction with Life Scale 
TBI – Traumatic Head Injury 
TFI – Tinnitus Functional Index 
TFS1 – Temporal Fine Structure 1 Test 
USD – University of South Dakota 
VA – Veterans Administration 
VAPHS – VA Pittsburgh Healthcare System 
VASFHS – VA Sioux Falls Healthcare System 
VINCI – VA Informatics and Computing Infrastructure 
WAIS-IV – Wechsler Adult Intelligence Scale – Fourth Edition 
WHODAS II – World Health Organization Disability Assessment Schedule II 
WIN – Words-in-Noise 

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Contents 
Protocol Title: .................................................................................................................. 6 
1.0 
Study Personnel .................................................................................................... 6 
2.0 
Introduction ............................................................................................................ 7 
3.0 
Objectives .............................................................................................................. 7 
4.0 
Resources and Personnel ................................................................................... 16 
5.0 
Study Procedures ................................................................................................ 18 
5.1 Study Design ........................................................................................................ 18 
5.2 Recruitment Methods ........................................................................................... 20 
5.3 Informed Consent Procedures ............................................................................. 26 
5.4 Inclusion/Exclusion Criteria .................................................................................. 26 
5.5 Study Evaluations ................................................................................................ 27 
5.6 Data Analysis ....................................................................................................... 27 
5.7 Withdrawal of Subjects ......................................................................................... 29 
6.0 
Reporting ............................................................................................................. 29 
7.0 
Privacy and Confidentiality .................................................................................. 29 
8.0 
Communication Plan ........................................................................................... 30 
9.0 
References .......................................................................................................... 31 
 

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Protocol Title:  Blast Exposed Veterans with Auditory Complaints 
1.0 
Study Personnel 
• Study personnel are listed below: 
 
Principal Investigator/Study Chair 
Sheila R. Pratt, Ph.D. 
VA Pittsburgh Healthcare System 
University Drive C (132-AU) 
Pittsburgh, PA  15240 
412-383-6537 
spratt@pitt.edu, Sheila.Pratt@va.gov 
 
Co-Investigators: 
 
Malcolm R. McNeil, Ph.D. 
VA Pittsburgh Healthcare System 
Research and Development (GA 128) 
University Drive C 
Pittsburgh, PA  15240 
412-414-3478 
mcneil@pitt.edu, Malcolm.McNeil@va.gov 
 
David Jedlicka, Au.D. 
VA Pittsburgh Healthcare System 
University Drive C (132-AU) 
Pittsburgh, PA 15240 
412-954-4647 
David.Jedlicka@va.gov 
 
Lindsey Jorgensen, Ph.D. 
VA Sioux Falls Healthcare System (and the University of North Dakota) 
2501 West 22nd Street 
Sioux Fall, SD  57105 
605-677-5474 
Lindsey.Jorgensen@usd.edu, Lindsey.Jorgensen@va.gov 
 
Frederick Gallun, Ph.D. 
Portland VA Medical Center 
3710 SW US Veterans Hospital Road (NCRAR) 
Portland, OR   97207 
503-220-8262 x57472  
Frederick.Gallun@va.gov 
 
Elizabeth Haley, Au.D. 

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VA Pittsburgh Healthcare System 
University Drive C (132-AU) 
Pittsburgh, PA  15240 
412-360-6456 
Elizabeth.Haley@va.gov 
 
Consultant: 
 
Gretchen Haas, Ph.D. (Consultant) 
 
VA Pittsburgh Healthcare System 
Research Building (1-A105) 
University Drive C 
Pittsburgh, PA  15240 
412-624-0331 
haasgl@msx.upmc.edu, Gretchen.Haas@va.gov 
 
 
2.0 
Introduction 
 
BACKGROUND AND SIGNIFICANCE 
 
Between October 1, 2001 and December 31, 2012 a total of 1,599,575 unique OEF/OIF 
and Operation New Dawn (OND) military personnel separated from active duty and 
became eligible for benefits through the Veterans Health Administration (Department of 
Defense, Defense Manpower Data Center, 2013).  Utilization data suggested that 
approximately 56% of these veterans have accessed some level of VA healthcare 
services, which is in contrast to the 28-24% utilization rate by the overall veteran 
population (National Center for Veterans Analysis and Statistics, 2013).  Among this 
population of veterans, traumatic brain injury (TBI) and post-traumatic stress disorder 
(PTSD) are evident at high rates and frequently are comorbid conditions.  Moreover, 
these two conditions are associated with substantially elevated healthcare costs. 
Auditory problems are a common complaint among veterans with TBI and PTSD even 
when hearing is normal upon standard audiometric testing; yet optimal methods for 
diagnosis and treatment of their auditory problems have not been well established or 
studied. Understanding and improving their auditory function could advance their 
interactions within the VA healthcare system, positively impact the services that they 
receive, affect their abilities to work and learn, and improve their quality of life. 
 
Mild Traumatic Brain Injury 
 
Traumatic brain injury is considered a signature injury of current and recent U.S. military 
engagements largely due to blast injuries (Wilk et al., 2010).  An estimated 20% of 
soldiers with blast injuries suffer from acute TBI with most cases being mild (Armed 
Forces Health Surveillance Center, 2010).   It is a significant healthcare issue among 
veterans with 10 to 15% of all OIF/OEF veterans having mTBI; a prevalence rate 
substantively higher than in the civilian population (Hoge et al., 2008). Sensory 
problems, such as hearing and vision loss are common in persons with mTBI especially 

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in persons with injuries due to blast exposure.  In the acute phase, individuals with mTBI 
complain of difficulties with headache, tinnitus, dizziness, nausea, fatigue, 
hypersensitivity, irritability, memory deficits, and depression (Sheedy et al., 2006).  
Cognitive deficits can be of the magnitude to interfere with daily activities (Alexander, 
1995) and typically include problems of attention and working memory (McAllister et al., 
2006), processing speed, verbal fluency (Ruff et al., 2010), comprehension and 
production of complex connected language (LeBlanc et al., 2006) and areas of 
executive function (Belanger et al., 2005).   Most adults with mTBI make a favorable 
recovery within days to weeks of injury but those with more severe injuries are inclined 
to exhibit persistent neuropsychological deficits (Bilger, 2008; Iverson et al., 2007).  The 
expression of symptoms is variable and a substantial number of individuals diagnosed 
with mTBI do not exhibit frank impairments upon neuropsychological testing (Tombaugh 
et al., 2007), although others will be symptomatic on both behavioral and 
neurophysiologic tests (Ruff et al., 2010).  An added complexity is that post-concussive 
symptoms associated with mTBI can manifest months or even years after the insult 
(Bales et al., 2009; Terrio et al., 2009).  These persistent and later emerging symptoms 
can result in long-term impairments of daily function with as many as 43% of individuals 
hospitalized for TBI reporting at least one unmet rehabilitative need at 1-year post-injury 
(Corrigan et al., 2010).  The delayed onset of symptoms might represent a gradually-
emerging consequence of the brain injury or a failure to detect persistent subclinical 
neurobehavioral signs of the injury (Ivins et al., 2009).   Regardless of whether these 
potentially handicapping symptoms are unidentified or late emerging, they represent a 
significant concern among returning OIF/OEF warriors and veterans. Similar findings 
are expected for veterans who only served in OND but their overall numbers are 
expected to be considerably smaller. 
 
Blast Injury 
 
Blasts have been responsible for about two-thirds of all combat injuries in the OIF/OEF 
conflicts (Murray et al., 2005), and although blast injuries have long been associated 
with modern warfare, the expansion of insurgent and terrorist tactics in these recent 
conflicts has been linked to increasing numbers of injuries and deaths due to the use of 
improvised explosive devices.  The blasts from these and other types of explosive 
devices are complex, as are the resulting injuries (Kocsis & Tessler, 2009; Wightman & 
Gladish, 2001).  Upon detonation there is rapid conversion of the explosive (solid or 
liquid) into gases that expand rapidly and in turn compress the surrounding air.  This 
initial pressure pulse is referred to as the blast overpressure.  As the gases continue to 
expand the air pressure drops behind the pressure pulse creating a relative vacuum or 
blast underpressure, which reverses the direction of the blast forces.  With high 
explosives the blast occurs instantaneous and the pressure waves propagate faster 
than the speed of sound.  Acoustic energy is compressed in front of the pressure pulse 
and eventually the blast waves deteriorate into acoustic waves (Wightman & Gladish, 
2001).  These extreme pressure changes can produce a shattering effect and 
barotrauma, which are considered the primary blast injuries.  Barotrauma results from 
excessive stretching and shearing due to differential acceleration and deceleration 
across the body relative to density.  The gas and fluid-filled structures of the body, such 

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as the lungs, bowel, and the middle ear are believed to be most vulnerable (Kocsis & 
Tessler, 2009).   
 
In warfare the injuries from blasts are heterogeneous and confounded by the secondary 
(projectiles), tertiary (effects of wind), and quaternary (burns, asphyxia, toxins) effects of 
blasts (DePalma et al., 2005; Wightman & Gladish, 2001).  Objects propelled by the 
energy of the explosions strike victims and cause blunt or penetrating ballistic trauma.  
Bodies can be propelled by the force of the blast and strike objects, and victims can be 
injured by structures collapsing onto them.  Additional injury can occur due to inhalation 
of toxic gases and exposure to chemicals resulting from the explosives, as well as 
resulting heat, fire and smoke.  Severe head injury is the leading cause of death due to 
blast with subarachnoid and subdural hemorrhage being the most common finding.  The 
brain is somewhat protected from the blast pressure waves because its water density is 
homogeneous but stress waves are capable of penetrating the skull (Chavko et al., 
2007) and in extreme cases can shatter the cranium from within (Wightman & Gladish, 
2001).  Brain injury also can occur as a consequence of injuries to other vulnerable 
organs, such as the lung, gastrointestinal track, heart, and long bones, producing air 
emboli, fat emboli, increased venous pressure, and hypoxia/ischemia that can result in 
more brain damage than the blast itself (Mayorga, 1997).  Because the brain is 
protected from the forces of the blast wave, most blast-related head injuries are 
believed to be secondary, tertiary and quaternary injuries (DePalma et al., 2005; 
Wightman & Gladish, 2001).  Yet evidence is mounting that the brain and spinal cord 
incur primary blast injuries from the pressure wave itself, although the injury 
mechanisms are unclear.   Furthermore, because of the advanced body armor worn by 
soldiers, damage to the central nervous system from combat-related blasts is 
increasingly attributed to the primary effects of the blast (DePalma et al., 2005; 
Haberstroh, 2004). 
 
Experimental animal models using shock and blast tubes have shown alterations of the 
central nervous system that are consistent with primary blast injuries.  Connell et al. 
(2011) used a guinea pig model and demonstrated that blast waves compress neural 
tissue and produce axonal membrane damage.  Similar studies with rats and rabbits 
have produced myelin disruption, defuse axonal damage, neuronal degeneration and 
increased oxidative stress (Cernak et al., 2001).  Blast injuries in animals also have 
been associated with behavioral changes and long-term learning deficits. 
 
Of the veterans exposed to blasts and associated acoustic trauma, neuropathologic 
changes have been reported and include small hemorrhages within white matter, 
chromatolytic changes in neurons, diffuse brain injury and subdural hemorrhage at the 
frontal and parietal convexities (Taber et al., 2006). Diffuse axonal injuries also occur 
often in the frontotemporal areas, the internal capsule, deep grey matter (such as the 
basal ganglia), upper brainstem and the corpus collosum.  Computer simulations have 
suggested that high stresses caused by primary pressure waves are associated with 
coup and contrecoup damage (Chafi et al., 2010) with orbitofrontal regions and the 
posterior fossa (cerebellum and brainstem) particularly susceptible.  Injuries also can be 
due to system reaction to the initial brain insult, such as swelling and oxidative stress.   

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In cases of mTBI many of the lesions and changes in brain matter remain undetected 
on MRI or CT scans (Niogi & Mukherjee, 2010), although improved imaging techniques 
are proving sensitive to the unique neurological abnormalities of this population.  
MacDonald et al. (2011) used diffusion tensor imaging and showed marked 
abnormalities in the middle cerebellar peduncles, cingulum bundles, and the 
orbitofrontal white matter when testing military personnel with blast-related mTBI, 
although their participants were mixed relative to the type of injury.  Davenport et al. 
(2012) studied two groups of OIF/OEF veterans with mTBI.  One group had mTBI due 
to blast exposure whereas the other group had non-blast related brain injuries.  They 
also used diffusion tensor imaging and found white matter disruptions with both groups 
but the disruptions were more diffuse with the blast-exposed veterans.  Moreover, the 
disruptions were more pervasive with increased number of blast exposures.   Multiple 
blast exposures is an issue with the OIF/OEF veteran population because military 
personnel with mild concussions often return to full duty status shortly after injury with 
about 85% being re-injured within 3 months of returning to duty (MacGregor et al., 
2011).      
 
Auditory Impairment and mTBI 
 
Hearing and visual impairments are common in persons with TBI and likely contribute to 
their communication, social and employment handicaps.  Furthermore, the more severe 
the TBI the more marked hearing loss tends to be, especially for high-frequency test 
signals.  Peripheral hearing loss is commonly associated with TBI particularly in blast 
injury cases with concurrent abnormalities of the central auditory system noted in some 
individuals (Fausti et al., 2009; Lew et al., 2007).  As indicated above, blast pressure 
waves can affect both fluid and gas filled structures, such as the ear, with the proximity 
and intensity of the blast influencing the magnitude of the injury (Lew et al., 2007; 
Patterson & Hamernik, 1997).  In the OIF/OEF conflicts, tinnitus and hearing loss have 
been responsible for the largest number of primary disabilities, with auditory problems 
being the fourth leading cause of medical referral for combatants returning from 
deployment (McIlwain et al., 2008).  Moreover, veterans with blast-related mTBI are 
more likely to have auditory complaints than non-blast related mTBI (Belanger et al., 
2011).  Auditory system injuries also are the most common single type of injury 
consequent to blast exposure, resulting in tympanic membrane perforation and middle 
ear and cochlear damage (Gondusky & Reiter, 2005; Patterson & Hamernik, 1997).  In 
a review of veterans’ post-deployment hearing status, Helfer et al. (2005) found that 
post-combat veterans were 50 times more likely to have ear-related problems than 
those who did not have combat experiences.  However, most of the reported auditory 
problems were peripheral in nature, usually middle ear and cochlear, and not 
necessarily associated with documented TBI (Gondusky & Reiter, 2005).    
 
Complaints of auditory problems with no peripheral hearing loss have been reported in 
individuals with known mTBI but their auditory complaints have not been studied widely 
or systematically, nor have effective treatments been established (Fausti et al., 2009; 
Lew et al., 2007).  Nonetheless, a recent publication by Gallun et al. (2012) reported on 

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standard audiometric and central auditory assessment results from 36 hospitalized 
OIF/OEF warriors with histories of blast exposure and a similar group of non-
hospitalized veterans with no blast exposures.  All of the blast-exposed warriors had 
been evaluated for TBI with 19 of 36 having a diagnosis of TBI, and upon interview, 13 
also indicated that they had symptoms of PTSD.  Although hearing handicap was not 
measured, 39% reported increased difficulty hearing in quiet and 78% reported more 
difficulty hearing in noisy environments since their blast exposures.  As expected, the 
two groups were similar and within normal limits on the standard audiometric measures, 
but differences emerged on some, but not all of the central auditory measures.  The 
blast-exposed patients were most notably different on several behavioral measures of 
central auditory processing and speech perception in noise (i.e., Gaps-in-Noise, 
Masking Level Difference, Staggered Spondaic Words, QuickSIN) and a long latency 
event-related potential test.  It should be noted, however, that on none of these tasks 
did a majority of the blast-exposed warriors demonstrate abnormal results.  
Furthermore, no soldier produced abnormal results on all of the central auditory tests, 
suggesting substantial group heterogeneity.  The composition of the blast-exposed 
group likely contributed (e.g., not all reported auditory complaints), but possible 
differences in the extent and location of the blast-related damage were considerations 
and highlight the complexity of this group of patients. 
 
Auditory problems experienced by blast-exposed warriors and veterans could relate to 
subclinical cochlear damage or indirect responses to damaged central auditory 
structures or compromised neural structures that subtend the auditory system.  Poor 
processing of auditory signals also might reflect difficulties in cognitive functions 
secondary to or supported by the auditory system.  For example, the reported difficulties 
might be due to reduced attention modulation of the auditory system or poor auditory 
working memory secondary to the brain injury.  However, for some individuals their 
problems likely reflect global cognitive deficits that are most noticeable within the 
auditory domain.  Common cognitive sequelae of TBI that might be related to or 
exacerbated by auditory dysfunction include difficulty comprehending complex language 
at pragmatic (Angeleri et al., 2008; Henchliffe et al., 1998) discourse (Coelho et al., 
2002) and sentence levels (Henchliffe et al., 1998; Le Blanc et al., 2006).  Sentence 
level processing has been identified as particularly vulnerable and sensitive to TBI.  For 
example, Hinchliffe et al. (1998) found the Revised Token Test (McNeil & Prescott, 
1978), a sentence level auditory processing test, to be the first factor selected in the 
identification of TBI, among 18 language factors investigated, and it predicted highly the 
other language and memory factors.  
 
As suggested above, individuals with mTBI are at high risk for poor post-discharge 
outcomes.  They often show decreased social and family integration and difficulty 
returning to work and school (Cattelani et al., 2002; Drake et al., 2000).  Difficulty 
dealing with auditory information and background noise likely contributes to their poor 
outcomes, although no published studies have examined this relationship to date.  
Veterans targeted by the current study are unlikely to receive appropriate referral 
because even soldiers who have both peripheral hearing loss and mTBI have low 
referral rates to audiology clinical services (Helfer et al., 2011).   Moreover, even if 

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referred, they have a reduced likelihood of receiving adequate auditory rehabilitative 
services due to their normal performance on standard audiometric test measures.  Yet, 
given the elevated incidence of mTBI in military and veteran populations, the scope of 
this problem is certain to grow as the remaining OIF/OEF warriors convert to veteran 
status and age-related hearing loss confounds their auditory processing difficulties.  A 
reflection of this increase is the formation of an online Auditory Processing Disorder 
group consisting of 36 VA audiologists who correspond regularly by email about how to 
best assess and treat these veterans.  Consistent concerns expressed by this group 
have related to test battery composition and management of patients once they have 
been identified and diagnosed. 
 
Post-Traumatic Stress Disorder and mTBI 
 
The coexistence of PTSD with mTBI is a confounding factor in OIF/OEF veterans with 
blast-related mTBI.   Hoge et al. (2008) found that approximately 44% of the returning 
OIF/OEF soldiers who reported loss of consciousness following blast injury met the 
criteria for PTSD.  In a similar study, Pietrzak et al., (2009) observed that approximately 
65% of their sample of OIF/OEF veterans with mTBI screened positive for PTSD, 
although loss of consciousness was not a strong predictor of comorbid PTSD, as was 
observed in the Hoge et al. (2008) study.   A range of psychosocial, somatic and 
cognitive problems are characteristic of PTSD such as flashbacks, nightmares, 
hyperarousal, and avoidance of stimuli related to traumatizing events, but a number of 
symptom overlap with mTBI including impaired concentration, headaches, irritability, 
anger and sleep disturbances (Ruff et al., 2010).  Persons with PTSD and mTBI also 
tend to experience problems with memory and appropriate modulation of attention.  
Veterans with both mTBI and PTSD also fair worse than veterans with isolated 
impairments in that they have greater health and psychosocial difficulties, poorer quality 
of life, and perceive themselves as having greater barriers to mental healthcare.  They 
also are more likely to experience employment and marital problems and unmet 
psychosocial needs.  Pietrzak et al. (2009) found that PTSD and related psychiatric 
conditions such as depression mediate the physical and post-concussive symptoms 
observed in mTBI veterans, suggesting that appropriate treatment of depression and 
PTSD symptoms might improve functional recovery of veterans with mTBI.  It also is 
possible that problems with hearing, which tend to increase the likelihood and severity 
of depression, can interfere with the treatment of mTBI and PTSD.   
   
Background Noise 
 
Difficulty listening in noise is a commonly reported complaint of persons with a history of 
TBI although the ability of this population to cope with and listen in background noise 
has not been well studied (Fausti et al., 2009; Landon et al., 2012).  It is not known 
whether they are hypersensitive to background noise as is common in cases of PTSD, 
are unable to focus attention on target sounds when background noise is present (e.g., 
listening in the dips), are unable to suppress background noise, or whether their 
auditory systems cannot process and separate or stream target signals from the 
background noise.  However, difficulty listening in background noise is not unique to 

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TBI.  It is nearly ubiquitous in person with sensorineural hearing loss due to damage to 
the cochlea and subsequent deterioration of the eighth nerve and central nervous 
system (Summers & Leek, 1998).   Background noise also is problematic for young 
children because of central auditory immaturity (Johnson, 2000) and elderly adults due 
to auditory aging and cognitive decline (Humes & Floyd, 2005).  For example, older 
adults with normal peripheral hearing usually perform similarly to younger adults on 
auditory language processing tasks in quiet but are more adversely affected in noise.  
Even after accounting for peripheral hearing loss, older adults hear speech less well in 
background noise, and have difficulties in attention-demanding situations such as when 
speech rate is increased, when processing or response rates are high, when speakers 
use a non-native dialect, or when linguistic, cognitive and memorial demand are 
increased (Burda, Scherz, Hageman & Edwards, 2003; Gordon-Salant & Fitzgibbons, 
2004; Humes & Floyd, 2005; Schneider, Daneman, Murphy & Kwong, 2000).  Older 
adults also have difficulty performing cognitive tasks (e.g., working memory tasks) in 
noise (Heinrich & Schneider, 2010).  Older adults appear to have more difficulties with 
voice segregation than do young adults, which have been attributed to problems with 
synchrony of coding (Schneider, Daneman & Pichora-Fuller, 2002).  Synchrony of 
coding allows access to the fine structure of speech signals, such as vocal F0 and 
harmonics, and facilitates the separation of speech from background noise and co-
occurring speech signals (Summers & Leek, 1998).   
 
Although not well studied, the auditory complaints of mTBI patients with normal 
audiometric test results appear to be similar in nature to those ascribed to older adults 
with normal hearing thresholds.  The parallels are of interest in accounting for and 
differentiating between the influences of peripheral and central auditory damage, as well 
as understanding mechanisms that impede efficient processing, but such an approach 
should be considered with caution as auditory decline in the aging model might not 
match with deficits associated with brain deficits due to traumatic insult.  
 
A common model of auditory perception, the Auditory Image Model (AIM; Patterson, 
2000) provides a general perspective on the possible auditory problems of blast-
exposed veterans.  The model argues that the auditory system forms images that are 
coded early at the level of the cochlea and eighth nerve, and then are integrated and 
processed as the auditory signals proceed through the central nervous system.  Recent 
work looking at the response to vowels and consonant-vowel syllables at the level of the 
eighth nerve and subcortical regions is consistent with this notion of early coding (e.g., 
Aikin & Picton, 2008; Krizman, Skoe & Kraus, 2010).  As such, breakdown and 
sensitivity to noise can occur very early in the system, and also becomes evident at 
higher cortical levels and possibly impacts cognitive and linguistic functions.   
Conversely, cognition and linguistic status can influence the manner in which primary 
signals and noise are processed by the auditory system.  Such an approach also 
supports the argument that auditory perceptual learning through exposure to modified 
input (e.g., cochlear implants, frequency and intensity shifted feedback, spectrally 
shifted vowels) and targeted perceptual training can influence performance across 
various levels of the auditory system.  However, the plasticity of the auditory system in 
blast-exposed patients likely is dependent on the nature and extent of their impairments. 

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Treatment Options 
 
There is a range of treatments for veterans with mTBI depending on the magnitude and 
type of injury, the presence of comorbid injuries, time post-injury and the presenting 
impairments.   After a patient is physically stable a number of rehabilitation approaches 
can be implemented (e.g., psychiatry, neuropsychology, speech-language pathology, 
rehabilitation and vocational counseling, physical therapy, occupational therapy), but 
unless a veteran has a hearing loss that is evidenced with standard audiometric test 
procedures the auditory intervention offerings are very limited.  Blast-exposed veterans 
with marked auditory complaints but normal audiometric test results appear to benefit 
from the use of assistive listening devices such as frequency modulated (FM) systems 
and hearing aids with remote microphones that can be configured to reduce the impact 
of background noise and reverberation (See preliminary studies).  There also is some 
evidence that these patients can benefit from auditory perceptual training procedures 
(Murphy et al., 2011; See preliminary studies), but acceptance and compliance with 
these device and behavioral treatment approaches are low.   
 
An untested treatment option is to amplify acoustic signals with mild-gain hearing aids in 
order to enhance the high-frequency portion of the speech spectrum.  Providing high-
frequency gain can increase contrast for the high-frequency speech cues that tend to be 
of lower intensity and more easily masked than mid- and low-frequency cues.  For 
example, Hornsby and Ricketts (2006) reported that by increasing high-frequency 
information, people with normal hearing demonstrated improved speech perception.  
Furthermore, even participants with flat hearing losses demonstrated substantive 
improvement with high-frequency emphasis.  They also benefited from extended high-
frequency bandwidths (Hornsby et al., 2011).  Woodall and Liu (2013) similarly found 
that enhancing vowel second formants improved vowel discrimination in persons with 
high-frequency hearing loss, although the investigators did not also enhance the third 
formant.  In addition to adding contrast, increased high-frequency gain might increase 
the acoustic drive to the central auditory system and reduce demands on the cognitive 
system.  For example, Heinrich and Schneider (2011) found that older adults benefited 
from added gain when performing an auditory memory word-association task with 
distorted words, in contrast to younger adults who failed to show the benefit.  They 
argued from a resource-allocation perspective that the added gain reduced the 
demands on cognitive resources that were used by the older adults to process and 
remember the distorted signals.  Pratt et al. (2007) observed a similar pattern with 
persons with aphasia secondary to left hemisphere stroke, where they required about 
+10 dB gain above that needed by non-brain-injured participants to perform an auditory 
language-processing task.  
  
Another potential benefit of fitting mild-gain hearing aids on individuals with mTBI and 
auditory complaints is that it is a relatively passive process and more likely to be 
adopted than auditory training and other behavioral treatment measures because it 
takes less effort, and is less obtrusive and visible than personal FM systems. 
Furthermore, mild-gain hearing aids have the potential of stimulating auditory plasticity 

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and perceptual learning because they are more consistent with the natural perceptual 
learning process, which does not require feedback and reinforcement (Seitz & Dinse, 
2007).  Most perceptual learning occurs with simple exposure and without conscious 
effort, which is quite different from the learning processes used in most auditory training 
programs.   So, although the use of mild-gain hearing aids will not result in substantive 
improvements in signal-to-noise ratio, as measured in the ear canal, the hearing aids 
might stimulate reorganization of the central auditory system such that there is improved 
filtering and segregation of signals from noise.  
 
Although anecdotal, audiologists at the VHAPHS have been offering mild-gain open-fit 
hearing aids to blast-exposed veterans with normal audiometric results for the last 4 
years out of frustration with the lack of practical treatment options.  Patient feedback 
has been positive with only one patient returning his hearing aids due to tolerance 
problems.  
  
3.0 
Objectives 
 
The purpose of the current proposal is to examine the characteristics and nature of this 
population’s auditory and auditory-related skills, and assess whether coexisting PTSD 
contributes to their deficits.  A group of these veterans will be grouped by whether they 
are symptomatic for PTSD, and will be compared to a control group of veterans without 
auditory complaints, and no PTSD or history of blast exposure.  Comparisons also will 
be made to a group of veterans with no significant blast histories and with disabilities 
limited to PTSD.  
 
After completing a clinical audiometric test battery, and PTSD, TBI, hearing handicap, 
and vision screens the veterans will complete measures of quality-of-life, central 
auditory processing, speech perception in noise, language processing and executive 
function to better understand various aspects of their ability to hear, remember, attend 
to and process speech and language through audition. The procedures will provide 
information about the loci of their auditory deficits and determine the extent to which 
language processing load and PTSD play a role. Secondarily, we will assess whether 
this population of veterans benefits from mild-gain open-fit hearing aids and if PTSD 
influences outcomes.  
 
The information obtained from this study will help us understand the auditory problems 
experienced by these veterans, and eventually contribute to the development of an 
efficient and effective assessment battery and intervention approaches.  This study is 
framed from both a behavioral and physiological perspective in order to document the 
problems experienced by this group of veterans.  The tasks in the current proposal will 
provide insight into this population of veterans and lay the groundwork for future 
research looking at auditory-specific disorders secondary to blast-exposure and mTBI.  
The current study also will provide background support for a more extensive 
intervention study with this population. 
 
Specific Questions to be Addressed 

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a. Across a range of central auditory processing, speech perception, psychoacoustic, 
verbal working memory, and language processing tasks, does this population of 
veterans differ from veterans who have normal hearing and no auditory complaints?  
Moreover, does the coexistence of PTSD influence performance? 
b. Are certain test procedures and stimuli particularly sensitive to the deficits found with 
this population of veterans and are deficit patterns influenced by the coexistence of 
PTSD? 
c. Does the addition of background noise produce over-additive effects in this 
population of veterans and does PTSD increase the effect? 
d. Does this population of veterans perceive and demonstrate benefit when fitted with 
hearing aids that provide mild high-frequency gain and does PTSD influence 
benefit? 
e. Is hearing aid benefit predictable by measures of auditory processing, speech 
perception, psychoacoustic, verbal working memory, and language processing?  
Furthermore, does the coexistence of PTSD influence the relationship between 
these measures and hearing aid benefit? 
 
Expected Outcomes 
 
a. This population of veterans will differ from veterans with no history of blast exposure, 
and the presence of PTSD will increase severity and alter the deficit pattern.  
b. This population of veterans will experience significant problems with the addition of 
background noise and the effect will be influenced by linguistic load, verbal working 
memory and attention.  
c. This population of veterans will demonstrate and perceive benefit from being fitted 
with mild-gain high-frequency hearing aids, although the coexistence of PTSD will 
restrict perceived benefit.  
d. Mild-gain high-frequency amplification will improve speech perception skills in quiet 
and noise, and improve linguistic processing and executive function.  
e. Benefit from amplification will relate to the deficits that the veterans present.  
  
4.0 
Resources and Personnel 
 
This study will be conducted at the VA Pittsburgh Healthcare System (VAPHS), the 
Portland VA Medical Center (PVAMC), and through the VA Sioux Falls Healthcare 
System with data collected at the University of South Dakota.  The personnel are listed 
below. 
 
Sheila Pratt, Ph.D. (VAPHS) will assume overall responsibility for the conduct of the 
proposed investigation and will be involved in all aspects of the proposed studies 
including project oversight, human subject IRB compliance, personnel training and 
supervision, task and stimuli refinement, subject recruitment and retention, protocol 
administration, data analysis and data dissemination. In addition, she will meet regularly 
with the research staff and Co-Investigators to establish short-term goals, monitor 

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progress, and resolve any problems that arise with respect to project implementation, 
data collection or data management.   
Malcolm McNeil, Ph.D. (VAPHS) will review unusual behavioral constellations, which is 
likely given the target populations. He also will play an important role during data 
interpretation and manuscript preparation. 
Laurie Smith-Seemiller, Ph.D. (VAPHS) will provide clinical and technical expertise in 
the areas of TBI and PTSD.  She also will facilitate the recruitment of participants.   
David Jedlicka, Au.D. (VAPHS) is a fulltime Clinical Audiologist in the VAPHS Audiology 
Clinic and will assist with participant recruitment and testing, and clinical data analysis 
and interpretation.  
Maureen Wargo, M.A. (VAPHS) is the Director of the VAPHS Audiology Clinic and will 
assist with participant recruitment and testing, and clinical data analysis and 
interpretation.  
Gretchen Haas, Ph.D. (VAPHS) will serve as a consultant and provide content support 
in her areas of expertise and will assist with data interpretation. 
Lindsey Jorgensen, Ph.D. (VASFHS and the University of North Dakota) will act as the 
lead investigator and co-ordinator for this project at the VASFHS and will be responsible 
for personnel training, protocol supervision, participant recruitment, protocol 
implementation, and IRB submission and compliance at the South Dakota site.  She will 
help coordinate activities between the project and the South Dakota and Nebraska 
Audiology clinical services. She also will be responsible for coordination of data entry 
and data monitoring at the VASFHS/University of South Dakota site, and will be actively 
involved in the dissemination of the results and manuscript preparation.   
Frederick Gallun, Ph.D. (PVAMC) will oversee the research and regulatory activities of 
the project at the PVAMC site, and work with Drs. Pratt and Jorgensen to maintain 
consistency across test sites.  Dr. Gallun and collegues recently completed a treatment 
study with the target populations and his technical support and research background will 
be vital throughout the project, especially during data interpretation and manuscript 
preparation.  
 
Bedda Rosario, Ph.D. (VAPHS, University of Pittsburgh) is a statistician at the 
University of Pittsburgh Epidemiology Data Center.  She will be responsible for the 
statistical analysis of the data.  She has a WOC appointment at the VAPHS. 
 
Elizabeth Haley, Au.D., (VAPHS, University of Pittsburgh) will act as the study 
coordinator and work with the study PI to oversee subject recruitment, experiment 
fidelity, data collection, regulatory compliance.  Elizabth has worked in Dr. Pratt’s lab 
previously and has a contract appointment through the University of Pittsburgh. 
 

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The study personnel who will obtain informed consent include: Sheila Pratt, 
David Jedlicka, Lindsey Jorgensen, Frederick Gallun, Elizabeth Haley and the 
study staff designated at each local site. 
 
The study personnel who will have access to identifiable data include: Sheila 
Pratt, Malcolm McNeil, David Jedlicka, Maureen Wargo, Laura Smith-Seemiller; 
Lindsey Jorgensen, Frederick Gallun, Elizabeth Haley and the study staff 
designated at each local site. 
 
A Data Use Agreements was approved for this project for the data collected 
through the VASFHS because data collection will occur at the University of South 
Dakota due to limited facilities and equipment at the VASFHS facility.    
 
5.0 
Study Procedures 
 
5.1 Study Design 
 
This study will consist of two parts.  Part 1 is diagnostic in nature, whereas Part 2 is a 
preliminary treatment study that will include a portion of the participants from Part 1. 
 
Part 1 Procedures 
 
The participants completing this study will be veterans between the ages of 20 and 50 
years and divided into 4 groups: 2 groups of 117 veterans who report histories of blast 
exposure and blast-related clinical signs consistent with the VA/DoD definition of mTBI 
(VA/DoD, 2009) and present with normal or near normal results on standard 
audiometric testing but who report substantive problems with audition; a group of 117 
normal hearing controls who report no auditory problems and no histories of blast 
exposure, brain injury, or psychiatric disorder (Normal Controls); and a group of 117 
normal hearing veterans with PTSD and no blast exposure or blast-related clinical signs 
(PTSD-only). Of the two groups of veterans with auditory complaints one group will 
present with little or no PTSD (mTBI-only), whereas the other group will be symptomatic 
for PTSD (mTBI+PTSD). A total of 468 participants will complete the study and 50 
additional participants will be allowed for experimental attrition. 
 
In addition to the 468 veteran participants, 468 family members or friends (significant 
others) will complete a questionnaire about the veterans’ hearing handicap. 
 
After a telephone screen and preliminary testing, a battery of behavioral and 
physiological measures will be administered to all 4 groups of veterans to characterize 
the level and nature of their auditory impairments. Included are tests and procedures 
that likely will capture underlying or related problems and are commonly used in clinical 
and experimental studies of the peripheral auditory system, central auditory processing 
disorders, speech and language perception in noise, and executive function in persons 
with brain injury.   
 

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Interested veterans will first be screened by telephone.  For those veterans who pass 
the screen, the testing (preliminary and experimental) will be conducted across multiple 
sessions at one of the study sites.  The first session will include the preliminary 
measures such as standard audiometric tests, questionnaires, and a vision screen to 
ensure appropriate inclusion and exclusion of participants.  The subsequent 
experimental sessions will include additional questionnaires and assessment 
procedures.  It is estimated that the preliminary and experimental testing will require 
about 8 to 12 hours, with the total time dependent on patient characteristics (e.g., 
fatigue, response speed, need for breaks, task tolerance).  It is anticipated that most 
participants will be able to complete all of the procedures in Part 1 within 4 to 5 
sessions, but 4 additional sessions will be allowed if more time, shorter sessions, or 
frequent breaks are needed. Our clinical experience with the targeted populations is that 
2 to 3 hour sessions are tolerated well and not burdensome.  Gallun et al. (2011) used a 
similar battery and test burden was not mentioned as a factor in their publication. 
 
Telephone Screen – After describing the study to prospective veteran participants, 
those who remain interested in participating will be asked a series of screening 
questions to ensure that they are within the targeted age range, can read and write well 
enough to complete the tasks, have no prior history of hearing aid use, have brain injury 
or disorder within the severity range targeted by the study, and whether they can be 
paid by direct deposit. Veterans passing the telephone screen and who wear corrective 
lenses will be asked to bring their glasses or contacts to the subsequent sessions so 
they will be able to complete forms, the Snellen screen, questionnaires, and other tasks 
involving visual processing. 
 
Preliminary Tests – Preliminary assessment procedures will be administered to 
determine group placement and exclude participants who might have difficulty 
completing the study.  The procedures include the following: 
a. A case history that includes questions targeting hearing, tinnitus, blast exposure, 
concussion, brain injury, PTSD, headache, pain, communication problems, 
academic histories, employment status and other demographic data (Attached). 
b. Brief Traumatic Brain Injury Screen (BTBIS; Schwab et al., 2006) to determine 
probable mTBI  
c. PTSD Checklist-Military Version (PCL-M: National Center for PTSD-Behavioral 
Division; Weathers et al., 1994) to screen for PTSD 
d. Hearing Handicap Inventory in Adults (HHIA, Newman et al., 1993) to document 
self-perceived hearing handicap.  It will be administered at the beginning and end of 
Part 1 to document baseline handicap status prior implementing Part 2 of the study. 
e. A standard audiometric hearing test battery that includes otoscopy, tympanometry, 
and an acoustic reflex screen at 1000 Hz, air- and bone-conduction pure-tone 
threshold testing (ASHA, 2005), and the Northwestern University Test # 6 (NU-6; 
Tillman & Carhart, 1966) 
f. Loudness discomfort levels (LDLs) for tones at 500, 1000, 2000 and 4000 Hz 
according to procedures recommended by Sherlock and Formby (2005) to document 
hyperacousis  
g. Snellen chart to screen vision 

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h. Motor-Free Visual Perception Test, version 4 (MVPT-4) to document that the 
subjects have the basic visual processing skills to perform tasks that include visual 
stimuli 
 
Table 1. Group inclusion criteria based on preliminary test measures. 
PRELIMINARY 
ASSESSMENT 
GROUPS 
mTBI-only 
mTBI+PTSD 
PTSD-only 
Normal 
Controls 
Blast Exposure 
History 
Yes 
Yes 
No 
No 
Normal or Near 
Normal Standard 
Audiometric Test 
Results 
Yes 
Yes 
Yes 
Yes 
History of Wearing 
Hearing Aids 
Consistently 
No 
No 
No 
No 
BTSI 
Evidence of 
Brain Injury 
Evidence of 
Brain Injury 
No Evidence 
of Brain Injury 
No Evidence of 
Brain Injury 
PCL-M 
<20 
>20 
>20 
<20 
HHIE 
>16 
>16 
Not 
considered 
< 16 
LDLs 
No 
Hyperacousis 
No 
Hyperacousis 
No 
Hyperacousis 
No 
Hyperacousis 
Snellen (corrected 
or uncorrected)  
20/30 
20/30 
20/30 
20/30 
MVPT-4 
>5th percentile >5th percentile >5th percentile 
>5th percentile 
 
 
Experiment Procedures 
 
Part 1 Procedures 
 
The experimental procedures are listed below according to type of assessment.  Most are 
commonly used clinical procedures and will be completed in the standard manner. 
 

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Health and Quality of Life Questionnaires –  
 
a. World Health Organization Disability Assessment Schedule II (WHODAS II) as a 
measure of general health status and quality of life (McArdle et al., 2005) 
b. Satisfaction with Life Scale (SWLS) to document health-related quality of life 
c. Brief Symptom Inventory-18 Item (BSI-18) to document self-perceived psychiatric 
and psychological status 
d. The Speech, Spatial and Qualities of Hearing Scale (SSQ; Gatehouse & Noble, 
2004) to assess self-perceived functional and situational auditory skills not covered 
by the other questionnaires. Like the HHIA, the SSQ will be presented at the 
beginning and end of Part 1 to establish the pretreatment baseline for Part 2. 
e. The Tinnitus Functional Index (TFI; Meikle et al., 2012) will be administered because 
many patients with mTBI and PTSD complain of tinnitus and it can impact perceived 
handicap and quality of life (Fagelson, 2007), although it should be noted that in our 
chart review of the target population tinnitus was not a primary complaint with only 
21.7% reporting any tinnitus.  
f. The Hearing Handicap Inventory for Adults-Significant Other (HHIA-SO; Newman & 
Weinstein, 1988) will be completed by a significant family member or friend (if 
available) to capture auditory-related problems noticed by others but not by the 
participants.  The veteran will give the questionnaire to a family member or friend to 
complete and mail to the study site.  These data will be kept confidential from the 
veteran, and the family members or friends can refuse to participate by not 
completing or mailing the questionnaire. 
g. HHIA will be repeated to document stability of handicap. 
h. Information about general medical history, blast and head injury, neurological 
history; audiology assessment history and behavioral health diagnosis and treatment 
history also will be collected from the VA Computerized Patient Record System 
(CPRS) to confirm status.   
 
Peripheral Auditory System – 
a. Distortion product otoacoustic emission (DPOAE) to assess cochlear integrity 
b. Fast Psychophysical Tuning Curves (FPTC) to determine filtering and spectral 
tuning properties of each ear.  The fast tuning curves will be obtained for 2000 and 
4000 Hz signals using the procedures and software developed by Sęk and Moore 
(2011).    
c. Temporal Fine Structure 1 test (TFS1; Moore & Sęk, 2009) to assess the ability of 
the cochlea to process fine acoustic structures.   
 
Central Auditory System –  
a. Tonal and speech Masking Level Difference (MLD) tests according to procedures 
described by (Wilson et al, 2003; Wilson et al., 1994). 
b. Competing Sentences subtest from the SCAN-3A to measure the ability to focus on 
a primary speech signal and ignore background speech 
c. Two-digits section of the Dichotic Digits Test (DDT; Musiek, 1983) to assess dichotic 
auditory function  

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d. Staggered Spondaic Word Test (SSW) to measure timing and  inter-hemispheric 
processing of words 
e. Gaps in Noise Test (GIN) to assess temporal processing in noise 
f. Auditory brainstem response (ABR), middle latency response (MLR), long-latency 
response (LLR) and active event-related P300 to assess the electrophysiological 
status of the central auditory system.   
 
 Speech and Language Processing in Noise –   
a. The Words-in-Noise test (WIN; VA Compact Disk 4.0; Wilson & Burk, 2005) to target 
listening at the single word level 
b. The Listening in Spatialized Noise - Sentences Test (LiSN-S; Cameron & Dillion, 
2012) to assess sentence perception in noise within a simulated 3-dimensional 
acoustic space  
c. Auditory and reading versions of subtests 1 through 10 from the Computerized 
Revised Token Test (CRTT and CRTT-R respectively; McNeil et al., 2009) will be 
administered in quiet and in +3 dB signal-to-babble to assess sentence level 
processing in both auditory and reading domains.  The preliminary CRTT pretests 
will be administered prior to these tests to assure that the participants have the basic 
skills to complete the tasks and to measure baseline reaction time. 
 
Executive Function – 
a. Digit span forwards and backwards both acoustically and visually according to 
Kemtes and Allen (2008) to assess verbal short term and computational memory 
skills 
b. The CRTT Stroop task (CRTT-R-Stroop; McNeil et al., 2010) to assess the 
interaction between language and executive function 
c. Rey Auditory Verbal Learning Test (Schmidt, 1996) to assess immediate and 
delayed verbal memory, efficiency of learning and the effects of interference 
d. Trail Making Test (Reitan, 1992) to measure attention and processing speed 
 
PART 2 Procedures 
Hearing Aid Fittings (treatment groups) – In Part 2 a subset of the participants from the 
mTBI-only and mTBI+PTSD groups from Part 1 will be fitted binaurally with open-fit 
hearing aids with mild high-frequency gain.  Each group will consist of 25 participants.  
They will be randomly selected and randomly replaced if they decline to participate at 
any point during the treatment protocol.   
Standardized fitting and verification procedures consistent with the American Academy 
of Audiology guidelines for audiologic management of adult patients will be used.   The 
hearing aids will be obtained through the VA hearing aid procurement procedures 
because the participants qualify for hearing aids due to their auditory impairment.  High-
end behind-the-ear hearing aids (Phonak Bolero Q90) will be fitted binaurally. The 
hearing aids will provide mild gain with high-frequency emphasis, which will be verified 
acoustically with real ear measures.  The noise suppression circuitry of the hearing aids 
will be activated but the frequency compression or shifting will be deactivated.  

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Additionally, to reduce the risk of sounds being too loud for the participants, Maximum 
Power Output will be set below the loudness discomfort levels of the participants. 
Prior to their hearing aid fitting the participants in the two treatment groups will complete 
the unaided portion of the Abbreviated Profile of Hearing Aid Benefit (APHAB, Cox & 
Alexander, 1995), along with the HHIA, and SSQ as pretreatment measures of self-
perceived hearing handicap, and situational hearing skills. To assess pre-fitting speech 
perception and language processing the California Consonant Test (CCT; Owens & 
Schubert, 1997) will be administered in the sound field at 65 dB HL in quiet and with 
multi-talker babble. 
Recovery of co-articulation (phonetic context effect) will be measured with a vowel 
identification task.  The vowels will be presented in the context of /d/ and /b/ sounds 
(Holte & Lotto, 2006).  The extent to which the consonant context changes the 
perception of vowel categories will be measured. 
As in Part 1 of the study, sentence level processing will be measured with the auditory 
and reading versions of subtests 1 through 10 from the Computerized Revised Token 
Test (CRTT and CRTT-R respectively) and will be administered in quiet and in babble to 
assess sentence level processing in both auditory and reading domains in optimal and 
adverse acoustic conditions.   
Follow-up Testing – The participants will be followed over a 6-month period.  One week 
(+/- 3 days) after the fitting the participants will be seen in the lab to re-verify the fit of 
their hearing aids and to determine any problems.  The hearing aid use-time will be 
recorded from the data-logging system of the hearing aids as a reflection of hearing aid 
benefit and to document the extent to which the participants are wearing their hearing 
aids.  During this session, both the aided and unaided portions of the APHAB will be 
administered along with the International Outcomes Inventory for Hearing Aids (IOI-HA; 
Cox & Alexander, 2002).  In addition, the participants will answer a single question 
about their likelihood to continue hearing aid use.  Intent to continue use tends to be 
related to user satisfaction with commercial products and service provision in other 
areas of healthcare.  The participants also will complete the HHIA, and SSQ.  The CCT, 
CRTT, CRTT-R and the phonetic context effect tasks will be re-administered with and 
without hearing aids.  
Home Visits – The participants will be visited in their homes by study staff at three 
different times: 1-, 2- and 4-months post-fitting (+/- 1 week).  The home visits will occur 
to reduce participant burden and encourage retention.  However, some participants 
might prefer to be seen in the lab or clinic than their homes, and if that is the case those 
participants will be accommodated.  Hearing aid use-time will be recorded from the 
data-logging system of the hearing aids and the hearing aids will be checked to 
determine appropriate function.  During these visits the HHIA, SSQ, APHAB, IOI-HA, 
and the intent to continue use question will be re-administered.  New hearing aid 
batteries will be provided and participants will be encouraged to wear their hearing aids 
for longer periods of time if their use-time is below 8 hours a day.  At 6-months post-
fitting (+/- 1 week) the laboratory follow-up testing will be repeated.  

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Delayed-Treatment Control Group – The participants in the delayed-treatment control 
group will be selected from the mTBI-only group and followed over a 12-month period 
(+/- 2 weeks).  At the onset of Part 2 they will complete the HHIA, SSQ, and the unaided 
portion of the APHAB.  They will complete the speech perception and language tasks 
administered to the treatment group (CCT, phonetic context effect, and CRTT tasks) but 
unaided only. The delayed-treatment groups will receive home visits at 1, 2, 4 months 
(+/- 1 week) post-entry, at which times they will complete the HHIA, SSQ, and the 
unaided portion of the APHAB. At 6 months post-entry their pure tone hearing 
thresholds will be measured to determine possible changes in hearing sensitivity, and 
the procedures used with the treatment groups will be applied with the same sequence 
of follow-up sessions.  
 
5.2 Recruitment Methods 
 
Part 1 Recruitment 
 
The participants (other than significant others) completing this study will be veterans 
aged 20 to 50 years and divided into 4 groups: 2 groups of 117 veterans who report 
histories of blast exposure and blast-related clinical signs consistent with the VA/DoD 
definition of mTBI (VA/DoD, 2009) and present with normal or near normal results on 
standard audiometric testing but who report substantive problems with audition; a group 
of 117 normal hearing controls who report no auditory problems and no histories of blast 
exposure, brain injury or psychiatric disorder (Normal Controls); and a group of 117 
normal hearing veterans with PTSD and no blast exposure or blast-related clinical signs 
(PTSD-only). Of the two groups of veterans with auditory complaints one group will 
present with little or no PTSD (mTBI-only), whereas the other group will be symptomatic 
for PTSD (mTBI+PTSD). A total of 468 participants will complete the study and 50 
additional participants will be allowed for experimental attrition.  It should be noted that 
the participants do not need to have a previous diagnosis of mTBI or PTSD, or even 
believe that they have mTBI or PTSD to participate in this study. 
 
All these participants (including normal controls) will be recruited using the following 
procedures.  They will be recruited through flyers distributed in various clinics (e.g., 
audiology, behavioral health, neuropsychology) at the three participating VA sites. In 
addition, participants will be recruited through research registries at the study sites and 
national VA and military research registries, such as the Corporate Data Warehouse 
through Data Access Request Tracker (DART) via the VA Data Portal/VINCI and the VA 
database for individuals who have initial positive TBI screens 
(https://vssc.med.va.gov/tbireports/TBI.aspx). The study will adhere to contact methods 
approved by the individual registries Flyers and list serve announcements will be 
provided to veteran organizations/offices at the university affiliates of the participating 
sites for distribution (flyer and announcement attached).  Flyers and list serve 
announcements also will be provided to local veteran organizations for distribution.  
Clinical audiologists at the three sites will be informed of the study and if they so 
choose, can provide potential participants with flyers so that the potential participants 
can contact study personnel to learn more about the study.   Research staff members 

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and investigators, when possible, will participate in public events for veterans (e.g., 
Research Week, VA athletic events and fairs, Veteran’s information tables at local 
university information and health fairs) where flyers and information will be offered about 
the study.  Potential veterans can provide contact information at the time of the events if 
interested in participating in the study, or they can contact the study personnel at a later 
time.   At the onset of the study and during Years 3 and 4, a review of audiology records 
in CPRS may be conducted for each site to identify possible participants based on 
target age range and normal or near normal pure tone audiometric test results.   These 
individuals will be sent a letter describing the study and inviting them to contact local 
study personnel if they are interested in participating in the study.  Also included in the 
mailing will be a stamped return envelope and a form that the veterans can return 
indicating that they would like to be contacted via telephone to discuss the study or opt-
out and not be contacted about the study.  Veterans who fail to return the form within 2 
weeks will be contacted by telephone by study staff members to determine if they 
received the mailing.  After the letters have been mailed, all information obtained from 
CPRS will be maintained in accordance with the VHA Records Control Schedule.  
Social Security Numbers will be used for CPRS access for recruitment, and then later 
for study data collection and subject payment purposed. 
 
The significant others completing the HHIA-SO will be a family member or friend 
selected by the veteran participating in the study.  The significant other is not required to 
complete or mail the questionnaire, and the veteran will not be penalized or withdrawn 
from the study if the questionnaire is no returned or if they do not have a person 
available or willing to complete the questionnaire.   
 
Part 2 
 
A subset of the participants from the mTBI-only and mTBI+PTSD groups from Part 1 will 
be selected to participate in Part 2.  They will be placed into four groups of 25.  The 
groups will consist of an mTBI-only treatment group and an mTBI+PTSD treatment 
group, along with an mTBI-only delayed-treatment control group and an mTBI+PTSD 
delayed-treatment control group.  
 
Using the order in which participants complete Part 2 as an identifier, the participants 
from the mTBI-only and mTBI+PTSD groups will be randomly assigned to receive either 
treatment or delayed treatment, and then ranked in random order for participation in 
Part 2. Each of the groups will be populated using this selection procedure.  The 
assignments will be determined at the onset of the study by the PI with subsequent 
replacement as needed.  Because Part 2 is preliminary in nature (not a randomized 
control trial) and includes low numbers of participants, any participants opting out of 
Part 2 will be replaced using the rank ordered list.  Participants will be informed at the 
conclusion of Part 1 whether they can enroll in Part 2.  If participants do not qualify, they 
will be informed that they could be contacted at a later date to act as a replacement.  
The study staff will be responsible for discussing enrollment in Part 2 with participants.   
 
Payment 

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The veteran participants will be paid $50 per session (laboratory and home visits) for 
their participation, and a $25 travel allowance for each session requiring travel to one of 
the testing sites. They will be paid through the preferred method at each site (e.g., 
Financial Management System, vouchers, payment cards).  When the Financial 
Management System is used the payment will not be immediate.  The significant others 
who complete the HHIA-SO will not receive any payment. 
 
5.3 Informed Consent Procedures 
 
The veteran participants will complete a telephone screen to ensure that they 
meet basic criteria and to reduce burden for those veterans who would not 
qualify from the onset.  The study will be described to them and if they remain 
interested in participation verbal permission will be requested to ask the 
screening questions (See script and flow chart for telephone screen.) 
 
Written and verbal informed consent will be obtained from the veteran 
participants before implementation of the remaining study procedures.  Two 
consent forms; one for each part of the study and will be completed.  The 
consent form for Part 1 will be completed by all participants and the consent form 
for Part 2 will only be signed by participants who complete Part 1 and are 
selected to complete Part 2.   Informed consent will be obtained from the 
participants in person in a private room by the investigators or study staff 
approved to obtain informed consent.  Human subjects protection requirements 
and how to obtain and document informed consent will be reviewed during the 
initial training of study personnel to insure procedural uniformity across sites.  
The training will occur at the beginning of the study and as new personnel are 
added to the study by the lead investigators at each site. 
 
Written and verbal informed consent will not be obtained from the significant 
others who complete the HHIA-SO.  The instructions will indicate that completion 
and mailing of the questionnaire will be voluntary and that all information on the 
questionnaire will be kept confidential and not accessible to the veteran.  No 
identifying information will be requested or included on the questionnaire except 
for the subject ID number assigned to the veteran participant.  
 
5.4 Inclusion/Exclusion Criteria 
 
The inclusion and exclusion criteria for the veteran participants will be based on the 
telephone screen and preliminary assessment procedures specified previously.  These 
procedures will be used to form the 4 participant groups and to insure that the 
participants can complete the tasks (See Table 1 above).   All of the participants will be 
aged 20 to 50 years, have normal or near normal audiometric test results, corrected or 
uncorrected vision of 20/30 or better, and no evidence of hyperacousis.  The mTBI-only 
group will have a history of blast exposure, evidence of possible brain injury, no 
significant symptoms consistent with PTSD, but elevated hearing handicap scores on 

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the Hearing Handicap Inventory for Adults (HHIA).  The mTBI+PTSD group will have a 
history of blast exposure, evidence of possible brain injury, significant symptoms 
consistent with PTSD, and elevated hearing handicap scores on the HHIA.  The PTSD-
only group will have no history of blast exposure or brain injury but they will have 
significant symptoms consistent with PTSD.  The Normal control group will have no 
history of blast exposure or brain injury, and little or no symptoms of PTSD (or other 
psychiatric disorder) or hearing handicap.  All of the veteran participant must not have a 
history of hearing aid use, or brain injury or disease more severe than that targeted by 
the study.  In addition, the veteran participants must be able to be paid for their 
participation. 
5.5 Study Evaluations 
 
All of the evaluations to be conducted are listed above under study procedures 
(5.1).  The data will be collected by the investigators and study staff.  The types 
of assessment methods vary and include questionnaires, review of records, 
behavioral tests, and physiological procedures.  Some data will be acquired via 
computer, while others will be administered face to face and via paper-and-
pencil.  
 
5.6 Data Analysis 
 
 
Part 1 Analysis 
 
Preliminary Analyses - The analysis will begin with basic descriptive statistics including 
means and standard deviations for continuous data and examination of distributional 
assumptions for all study measurements including the questionnaire data (e.g., HHIA, 
WHODAS-II, SSQ and HHIA-SO) for each group of interest.  These analyses will be 
used to evaluate the extent of missing data and to identify outliers.  
 
Primary Analyses - Random Forests (RF, Breiman, 2001) will be applied to determine 
which auditory, language processing, and executive function variables best discriminate 
the three groups.  This technique performs variable selection and the variables are 
ranked by Gini score, a measurement of average accuracy of all trees containing a 
particular variable.   One-way ANOVA will be used to determine differences between 
groups for normally distributed continuous data.  Analysis of covariance (ANCOVA) will 
be used to adjust for differences between groups.  If assumptions for the parametric test 
are not met, a non-parametric alternative will be used (e.g., Kruskal-Wallis, non-
parametric ANCOVA).  The p-values will be adjusted for multiple testing by using a false 
discovery rate method whenever more than one variable is being tested.  Statistical 
assumptions (e.g., linearity, normality) will be verified prior to hypothesis testing.  All 
statistical analyses will be two sided and the significance level will be 0.05.   
 
Sample Size and Power - A sample size of 117 per veteran group will achieve 80% 
power at a 0.05 significant level to detect an effect size (i.e., odds ratio) of 2.50.  This 
sample size was computed based on an adjustment that was made assuming that a 
multiple regression of the independent variable of interest on the other independent 

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variables in the model will result in an R-squared of 0.20.  For one-way ANOVA, the 
total sample of 468 subjects achieves 80% power to detect an effect size of 0.18 or 
larger with a two-sided significance of 0.01 to account for multiple hypotheses testing.  
For analysis of covariance, the study is powered (0.80) to detect an effect size of 0.16 
assuming the strength of the relationship between the response of interest and the 
covariates, measured as R-squared, is 0.20. 
 
Part 2 Analysis 
 
Primary Analyses – Basic descriptive statistics will be computed and examination of 
statistical assumptions will be performed for all study measurements.   For 
questionnaire data, analysis of variance (ANOVA) or Kruskal Wallis test will be used to 
determine differences in the overall and subset scores between the mTBI groups.  The 
analysis will also include basic descriptive statistics for behavioral data test measures at 
baseline and at 6 months for the mTBI-only and mTBI+PTSD groups, and at baseline 
and 12 months for the delayed-treatment groups.  We will focus on the changes in the 
behavioral test measures from baseline to 6 months (mTBI-only and mTBI+PTSD 
treatment groups) and from baseline to 12 months (delayed-treatment groups).  
Specifically, paired t-test or Wilcoxon signed rank test will be used to determine change 
at 6 or 12 months and this test will be applied to each behavioral test measure 
separately.  False discovery rate will be used to adjust the p-values for multiple 
hypotheses testing.   All statistical analyses will be two sided and the significance level 
will be 0.05. 
 
Secondary Analyses – For longitudinal analysis, the data will be modeled using linear-
mixed models for which the outcome is the behavioral test measure across time.  The 
predictors will include time, group and interaction between group and time.  Covariates 
will be added to the model as needed.  In addition, variables with a high Gini score from 
Part 1 will be correlated with final hearing aid results as a preliminary investigation of 
whether hearing aid benefit can be associated by any of the variables obtained above.  
We will measure correlations using either Pearson’s or Spearman’s correlation 
coefficient.  We will adjust the p-values for multiple testing by using a false discovery rate 
method whenever more than one variable is being tested.  Single-subject design metric 
also will be used to investigate individual responses to the hearing aid treatment. 
 
Sample Size and Power – This analysis will include data from 100 participants (25 for 
each group).  For any comparisons of the four groups based on ANOVA with a 
significance level of 0.01 to account for multiple comparisons and a power of 0.80, an 
effect size of 0.38 or greater will be detectable.  For the paired analyses described 
above, there is sufficient power (0.80) to detect an effect size of 0.50 (baseline versus 6 
months) or 0.50 (baseline versus 12 months), or greater assuming a two-sided 
significance level of 0.01 to account for multiple comparisons. For the longitudinal 
modeling, there will be sufficient sample size to support the proposed modeling that will 
allow approximately 10 observations to be estimated for each parameter. The number 
of covariates in each model will depend on the sample size to insure that there are 
approximately 10 observations available for each parameter estimated.  For correlation 

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based analyses, the study is powered (0.80) to detect correlations of 0.26 or greater in 
absolute value for a total sample size of 100.   
Once the data are formatted and cleaned by a staff member at the VA Pittsburgh 
site under the supervision of the statistician, the data will be analyzed by the 
statistician.   
5.7 Withdrawal of Subjects 
 
Participants can be withdrawn from the study by the investigators and study staff 
if they do not meet all of the inclusion criteria, have more than 4 no-show 
appointments without excuse, demonstrate non-compliance on study tasks, 
exhibit excessive frustration and emotional reactions to study procedures that do 
not subside with re-instruction, discussions about the purpose of the tasks, 
breaks or rescheduling.   
 
Participants can withdraw at any time without penalty. They can inform an investigator 
or study staff in person, by telephone or in writing.  Participants withdrawn from the 
study will be informed in person or by telephone by an investigator or study staff.   All 
participants who withdraw or are withdrawn from the study will be supplied with form 10-
1016 - Revocations for use and release of IIHI for VHA Research. 
 
All of the participants with hearing impairment will be referred to their local VA for 
audiological services and follow-up.  Participants with PTSD will be referred to their 
local VA for behavioral health services if they are not receiving services currently.   
 
6.0 
Reporting 
 
The occurrence of Serious Adverse Events, Unanticipated Problems and 
Protocol Deviations will be reported to the local lead investigator via telephone, 
encrypted VA email, or in person with documentation submitted to the project PI 
though encrypted VA email or in person. A report will be developed by the local 
lead investigator and submitted to the VA Central IRB through its secure 
SharePoint site, and as required to the local site R&D Committee.    
 
7.0 
Privacy and Confidentiality 
 
Protected Health Information will be collected during the course of this study but not 
disclosed outside of approved study investigators and staff.   The following include the 
steps that will be taken to ensure participant privacy and confidentiality. 
• All paper records with identifiable information will be retained at each site in a 
locked cabinet within a secure laboratory space. 
• All coded paper records with will be retained at each site in a locked cabinet in a 
secure laboratory space and kept separate from all identifiable information. 
• The study PI and each site will retain linkage code documentation that is kept 
secure and separate from data and other identifiable information. 
• Only information related to the study will be requested and obtained. 

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• Only investigators and study staff will have access to identifiable participant 
information and data. 
• The laboratory desktop computers with custom and non-VA software used for 
data acquisition will be password protected and disconnected from the internet 
and VA intranet.  Laboratory desktop computers connected to the VA intranet will 
be used for administration of questionnaires and data entry into REDCap.  We 
will use the VA-approved version of REDCap within the VA Informatics and 
Computing Infrastructure system (VINCI).  The VINCI system also will be used 
for data storage and analysis.  Laboratory laptops will be encrypted per VA 
guidelines, password protested and blocked from internet use. 
• Coded raw data residing on the laboratory computers will be copied onto storage 
drives for backup at each site.  These drives will be in physically locked and 
secured laboratory spaces. They will be encrypted to FIPS 140-2 standards and 
approved by the site ISOs prior to purchase and use.  It should be noted that the 
PI currently uses this type of backup system in her laboratory. 
• Some data will be transferred to the drive allocated to the study PI on the VAPHS 
research server (currently is the “L:\Hearing_Lab). . However, most of the raw 
data acquired from this study will be acquired and stored in the VA-approved 
version of REDCap with the VINCI system or directly inputted into VINCI for 
storage.  These data will be coded with access limited to study investigators and 
staff.   
• No identifiable data will be included in presentations and publications. 
• Interviews and private study related conversations will be conducted in private 
rooms. 
• After participants have provided informed consent to participate in the study, 
contact relating to scheduling, session reminders, and participant questions 
about non-sensitive information will be allowed by e-mail and telephone text if 
preferred by the individual participants.  No sensitive information will be 
transmitted my e-mail or text. 
 
8.0 
Communication Plan 
 
The PI and lead investigators will have conference calls at least twice per month to 
maintain coordination of the study activities and to address any issues.  Once a year, 
the PI will meet face-to-face with Drs. Jorgensen and Gallun and their respective study 
teams to check procedural fidelity and data integrity.  Additional meetings will be 
scheduled as needed.    
 
Data monitoring will occur monthly by the lead investigator at each sites with monthly 
reports submitted to the PI for review and signature.  The participant safety and data 
accrual, security, and fidelity will be reviewed by site and in aggregate. In addition, all 
three teams will complete yearly internal audits to confirm the fidelity of their procedures 
and documentation, and to insure appropriate data quality and security. The results of 
these audits also will be reviewed by the PI with corrective actions taken and reported 
as needed.  The data accrual is expected to be 50% at the Pittsburgh site, 25% at the 
PVAMC site and 25% at the VASFHS/University of South Dakota site.  If more than 5% 

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of participants per year per site have protocol deviations, the study personnel at that site 
will receive re-training.  The lead investigators at each site will receive copies of the 
documents approved by the Central IRB for the study, and the documents required for 
submission at the local site. 
To ensure that all regulatory and IRB requirements have been met at each site prior to 
implementing the study procedures, the lead investigators at each site will submit a 
copy of the local IRB application, consent forms, HIPAA documents and  approval 
letters to the PI.   
Copies of all Central and local IRB documents will be retained in regulatory binders by 
the PI and the lead investigators at each site will retain copies of the Central IRB 
documents transmitted to them, as well as their local IRB documents. 
Serious Adverse Events and Unanticipated Problems will be reported to the lead 
investigator at each site who will contact the PI.  Documentation will be submitted to the 
Central IRB by the lead investigator with copies submitted to the PI.  Copies of the 
reports will be retained by the PI and the lead investigator at their site.  The PI also will 
submit interim results that may impact conduct of the study. 
All sites will continue to collect data until the full complement of participants has 
completed the study or until the study has been concluded.   
 
9.0 
References 
 
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