Cochlear Promontory Stimulation for Treatment of Tinnitus: Towards Developing an Implantable Device
Phase: NA
Conditions: Tinnitus
Sponsor: Mayo Clinic

 
 
Cochlear Promontory Stimulation for 
Treatment of Tinnitus: Towards Developing an 
Implantable Device 
 
NCT03759834 
 
13September2022 

 
COCHLEAR PROMONTORY STIMULATION FOR 
TREATMENT OF TINNITUS: TOWARDS DEVELOPING 
AN IMPLANTABLE DEVICE 
 
Principal Investigators: 
Matthew L. Carlson1, MD 
 
Co – Investigators:  
E. Matthew Hoffman3, DO, PhD; Nicole M. Tombers1, RN, CCRP; Jeffrey P. Staab4, MD; Amy 
M. Tuchscherer1, CCRC; Ashlee P Kirtz1; Melissa D. DeJong2, AuD; Jill M. Gruenwald2, AuD; 
Corey A. Stoelb2, AuD; Kaitlyn E. Caceres2, AuD; John P. Marinelli1, MD 
 
Institutional affiliations:  
1Department of Otorhinolaryngology, Mayo Clinic, Rochester, MN, U.S.A..; 2Division of 
Audiology, Mayo Clinic, Rochester, MN, U.S.A.; 3Department of Neurology, Mayo Clinic, 
Rochester, MN, U.S.A; 4Department of Psychiatry, Mayo Clinic, Rochester, MN, U.S.A. 
 
 
 
 
 
 
Version 23 
September 13, 2022

 
Page 1 of 13 
 
TABLE OF CONTENTS 
Page 
STUDY SUMMARY …………………………………………………………………….……. 3 
1. BACKGROUND ………………………………………………………………….…… 4 
2. STUDY OBJECTIVES …………………………………………………………….…. 6 
3. STUDY DESIGN …………………………………………………………………….…6 
4.1   General Design   ……………………………………………………………….… 6 
4.2    Primary Study Endpoints   ……………………………………………….……… 7 
4.3    Secondary Study Endpoints   ………………………………………….………… 7 
4.4    Early termination…………………………………………………….……………7 
4.4    Risks / Benefits……………………………………………………….……………7 
     5.    SUBJECT ENROLLMENT AND WITHDRAWAL ……….………….……………. 8 
 
 
5.1    Inclusion Criteria   …………………………………….………….……………… 8 
 
 
5.2    Exclusion Criteria   ………………………………………………….…………… 8 
 
 
5.3    Subject Recruitment   ……………………………………………………………. 8 
 
 
5.4    Withdrawal of Subjects   ………………………………………………………… 8 
    6.     STUDY PROCEDURES ………………………………………………………………. 9 
 
 
6.1    Pre-Clinical Visit   .………………………………………………………………. 9 
              6.2    Clinical Visit   ………………………...………………………………………….. 9 
 
 
 
6.2.1    Promontory Stimulation   …………………………………………………. 9 
 
 
6.3    Post Procedural Assessment  ……………………………………………...……..11 
    7.      DATA COLLECTION AND ANALYSIS   …………………….……...…………… 11 
 
 
7.1    Data to be Collected   ……………………………………..….…….…………..  11 

 
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8.       DATA HANDLING ……………………………………………….………………....… 13  
9.       STUDY FUNDING ………………………………………………………………..…… 13 
10.      REFERENCES ……………………………….……………………….……...……….   14 
APPENDIX A (PROMONTORY STIMULATION) ………………………….……….…..  15 
 
 
 
 
 

 
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STUDY SUMMARY 
 
Title:  Cochlear Promontory Stimulation for Treatment of Tinnitus: Towards Developing an 
Implantable Device 
IRB Protocol Number:  17-004832 
Methodology: Prospective, investigational  
Target subject accrual: 100 
Expected duration of study: 10 years 
Subject participation duration: 4 days [3 sequential clinic visits scheduled 7 days (+14/- 2 days) 
apart with a 3 month follow up visit]  
Primary Objective: Use of a cochlear promontory stimulation electrode to provide safe, short 
term relief of tinnitus.  
Secondary Objective: Map the optimum regions of the cochlear promontory in planning for an 
implantable electrical device for long term tinnitus suppression. 
Principal Investigator: Matthew L. Carlson, MD 
 
 
 
 
 
 
 
 
 
 
 

 
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1   BACKGROUND 
Tinnitus is the perception of sound when no external noise is present.  The exact mechanism(s) 
underlying the development and maintenance of tinnitus remains largely unknown.  The Center 
for Disease Control (CDC) estimates over 50 million — nearly 15% of the general public —
experience some form of tinnitus [9]. Roughly 20 million people struggle with burdensome 
chronic tinnitus, with 2 million experiencing extreme and debilitating symptoms [9].   
Currently, there are no Food and Drug Administration (FDA) approved pharmacological 
therapies or surgical devices available for the treatment of tinnitus. The 2014 Clinical Practice 
Guideline on tinnitus from the American Academy of Otolaryngology – Head and Neck Surgery 
summarized the existing state of tinnitus management by stating “A cure for primary tinnitus 
does not yet exist, and despite claims to the contrary, no method has been proven to provide 
long-term suppression of tinnitus.” Existing treatment methods largely focus on counseling, 
cognitive behavioral therapy, masking, and sound therapy for habituation – strategies that may 
render tinnitus more tolerable, but do not abolish the symptom.  
To date, the preponderance of research evaluating the feasibility of electrical stimulation for 
suppression of tinnitus comes from studies examining cochlear implantation and promontory 
stimulation [7]. Cochlear implantation is currently the gold standard for rehabilitation of severe to 
profound sensorineural hearing loss and a demonstrated byproduct of cochlear implant 
electrical stimulation is tinnitus suppression. A recent review of the literature evaluating the 
efficacy of cochlear implantation for treatment of tinnitus in patients with single-sided deafness 
reveals that tinnitus is improved in 82% to 100% of implantees, abolished in 14% to 100% of 
implantees and none of the studies reported worsening of tinnitus during device use [10]. 
Despite these promising findings, cochlear implantation cannot be feasibly applied to patients 
with normal to moderate hearing loss, which comprises the majority of the population with 
tinnitus, since placement of an intracochlear electrode commonly results in significant hearing 
loss or deafness. 
Promontory stimulation is an established otologic procedure that was initially developed as a 
diagnostic tool to assess patient candidacy for cochlear implantation. Promontory stimulation is 
most commonly performed in the outpatient setting on an awake patient by placing a single 
insulated probe through a topically anesthetized tympanic membrane and applying monopolar 
current for several seconds to minutes. The safety and efficacy of transtympanic promontory 
stimulation for the temporary relief of tinnitus in patients with normal hearing and varying 
degrees of hearing loss has recently been evaluated [3]. Overall, the literature supports that 
45% to 86% of subjects gain significant or complete suppression of tinnitus according to 
different measures and varying stimulation parameters. Furthermore, in most cases, electrical 
stimulation can be successfully administered with either no perception or only transient and 
minimal perception [4]. When evaluating the efficacy of tinnitus suppression according to 
underlying etiology, it has been found that patients with acoustic trauma or noise-induced 
hearing loss had the highest success rates of tinnitus suppression compared to other etiologies 
such as presbycusis or Ménière's disease [5]. However, most patients only experience tinnitus 
suppression during and shortly after active electrical stimulation, with a smaller subset enjoying 

 
Page 5 of 13 
 
residual inhibition for hours to days after treatment [5-6]. Thus, while successful at providing 
temporary reprieve, the method of transtympanic promontory stimulation utilizing an external 
system does not provide a solution to manage chronic tinnitus. To suppress tinnitus long-term, 
patients must have access to continuous or repetitive electrical stimulation. 
From these data, the investigators hypothesize that a partially- or totally-implantable device, 
capable of administering electrical stimulation via cochlear surface (i.e., promontory), will 
provide safe and effective long-term suppression of tinnitus in patients with normal to moderate 
sensorineural hearing loss. Paramount to the development of an implantable device, the 
optimum region(s) of device placement in relation to the cochlear turns (i.e., basal, mid, apical 
or multiple levels) must be evaluated.  Placement of the electrode in the region of the 
posteroinferior promontory or at the round window can effectively stimulate the basal turn of the 
cochlea, which corresponds to high-frequency regions of the tonotopic map. In contrast, 
placement in the region of the anterosuperior cochlear surface, inferior to the cochleaform 
process for example, can stimulate the mid- and apical turns of the cochlea, which correspond 
to mid- and low-frequency regions of the cochlear tonotopic map. Several studies have 
demonstrated successful electrical suppression of tinnitus through promontory stimulation in the 
region of the round window, while other studies have suggested that the region of optimal 
stimulation varies across subjects and more complete “cochlear coverage” is beneficial [11].   

 
Page 6 of 13 
 
3   STUDY OBJECTIVES 
 
Primary Objective: To characterize the safety and efficacy of cochlear promontory stimulation 
in the short-term relief of tinnitus.    
Hypothesis: Cochlear promontory stimulation is a safe procedure that provides short term 
tinnitus relief to a select subset of patients with chronic tinnitus. 
 
Secondary Objective: To determine the optimum region(s) of the cochlear promontory in 
planning for an implantable electrical device for long term tinnitus suppression.   
Hypothesis: Electrical suppression of tinnitus is dependent on the cochlear tonotopic map, with 
an optimum region for tinnitus suppression individualized to each patient.   
 
4   STUDY DESIGN 
4.1   General Design 
 
1. Experimental approach: adult patients with normal to moderate hearing loss and 
disruptive intractable asymmetric tonal tinnitus will be recruited for electrical promontory 
stimulation testing.  
2. Candidate subjects will undergo a temporal bone Computed Tomography (CT) scan, 
contrast enhanced head Magnetic Resonance Imaging (MRI), audiogram with 
immittance testing, pitch and level matching of tinnitus, Distortion Product Otoacoustic 
Emissions (DPOAE) and Auditory Brainstem Response (ABR) testing prior to 
promontory stimulation. Head MRI, DPOAE, audiogram and immittance testing are 
considered clinically routine for assessment of asymmetric tinnitus. Temporal bone CT, 
ABR, tinnitus pitch, level matching, masking levels and residual inhibition testing are not 
standard clinical assessments for asymmetric tinnitus. In addition, subjects will complete 
the Tinnitus Handicap Inventory (THI), Tinnitus Functional Index (TFI) and Tinnitus 
Visual Analog Scale (VAS)-L (loudness) and Tinnitus VAS-A (annoyance) 
questionnaires three separate times within the 10 days prior to promontory stimulation 
testing. Additional testing for comorbid anxiety and depressive conditions will be a 
screening Generalized Anxiety Disorder (GAD7), Patient Health Questionnaire (PHQ8), 
and short Health Anxiety Inventory (HAI-S). The NEO Personality Inventory (NEO PI) will 
be administered to provide baseline information.  The initial session of promontory 
stimulation will define safety stimulation parameters, with a continual treatment after 
defining these parameters. After treatment is completed, the patient will complete the 
THI, TFI, and Tinnitus VAS-A and Tinnitus VAS-L immediately prior to stimulation, during 
stimulation, and following completion of stimulation at 10-minutes, 1-hour, 24-hours, 48-
hours, and 1-week (or prior to the next scheduled stimulation treatment, whichever 
occurs first) following completion of stimulation. There will also be a “recall survey” in 
which patients will recall the time and feeling that their tinnitus felt in the week after the 
stimulation procedure.  In addition, pitch and level matching of tinnitus will be completed 
prior to the first promontory stimulation session and after the last session. Each patient 

 
Page 7 of 13 
 
will undergo three successive treatments separated by 7 days (+14/- 2 days). Prior to 
each treatment, the patient will receive an audiogram and DPOAE testing to document 
interval safety. At the conclusion of the study, subjects will be asked about their 
willingness to undergo surgical implantation of a device capable of long-term scheduled 
or on-demand electrical stimulation for tinnitus suppression.  
4.2   Primary Study Endpoints 
The primary study endpoints include tinnitus relief based upon questionnaires and tinnitus 
matching, tactile and auditory feedback, and the perception of discomfort during stimulation.   
4.3   Secondary Study Endpoints 
The secondary study endpoints include determining treatment parameters of the cochlear 
promontory for maximum tinnitus suppression.   
 
4.4   Early termination 
If during the pilot study the placement or use of the cochlear promontory stimulation electrode is 
documented or suspected by the surgeon to cause sensorineural hearing loss or undue 
discomfort, the study protocol will be revisited and re-written or the study will be terminated. 
4.5 Risk / Benefits 
Benefit: We propose a study evaluating short term suppression of tinnitus with the information 
accumulated to aid in the development of a future implantable device capable of providing long 
term tinnitus suppression.   
Risk: There is a 1.6% risk of persistent tympanic membrane perforation; the risk of perforation 
requiring intervention is 0.5% [13].  The risk of electrical current spread on the surface of the 
promontory could theoretically cause facial nerve stimulation, discomfort through stimulation of 
the tympanic plexus, or hearing loss. CT scans involve exposure to radiation. The amount of 
radiation from these studies has a low risk of harmful effects. 

 
Page 8 of 13 
 
5   SUBJECT ENROLLMENT AND WITHDRAWAL 
5.1   Inclusion Criteria 
• 
Age: 18 years of age or older 
• 
Normal to moderate sensorineural hearing loss (based on PTA of 500, 1000 and 2000 
Hz) and a word recognition score equal to or greater than 60% 
• 
Asymmetric or unilateral subjective tonal tinnitus  
• 
Tinnitus that is disruptive by at least two of the three criteria: 
o Determined by THI score (in the severe range i.e. ≥56/100) 
o TFI (in the severe range i.e. ≥52/100) 
o Tinnitus VAS (≥ 5/10 ) 
• 
Tinnitus that is intractable, and has not been ameliorated by conventional measures 
such as a hearing aid or masking, when such interventions are potentially clinically 
indicated (e.g., it is not expected that people with minimal or no hearing loss would trial a 
conventional hearing aid) 
• 
MRI of the head that does not reveal any anatomical or structural abnormalities of the 
inner ear, cochlear nerve, or brainstem that would negatively impact response to study 
intervention (e.g., vestibular schwannoma) 
 
5.2   Exclusion Criteria 
• 
Age: less than 18 years of age 
• 
Subjectively severe tinnitus present less than 6 months or longer than 12 years; it is 
permissible to include people who have had intermittent or constant tinnitus longer than 
12 years as long as it was not perceived as severe longer than 12 years 
• 
History of brain or major ear surgery  
• 
Prior major head trauma, defined for the purposes of this study as head trauma that 
results in sudden injury that causes damage to the brain and results in lasting cognitive 
impairment 
• 
Ongoing clinical diagnosis of depression or anxiety; for the purposes of this study, it is 
permissible to include people who: 1. have a past history of clinically diagnosed 
depression or anxiety that is no longer currently active; or 2. people who have 
depressive or anxious symptoms that are thought to primarily result from severe tinnitus  
o Determined by screening using the GAD 7, PHQ8, and HAI-S 
▪ 
GAD7 > 9 (indicates clinically significant anxiety) 
▪ 
PHQ > 9 (indicates clinically significant depression) 
▪ 
HAI-S > 25 (hypochondriacal level illness anxiety) 
• 
Inability to assess, continue or complete trial 
• 
Currently on regularly scheduled antidepressants, anxiolytics, or antipsychotics; for this 
study, it is permissible to include people who use such medications at lower doses as a 
sleep aid or for people who intermittently use such medications for situational anxiety 
(e.g., Ativan before airplane travel) 
• 
Active use of other tinnitus treatments; for the purposes of this study it is permissible to 
include people who prefer to use a hearing aid to amplify ipsilateral hearing loss  
• 
Known pregnancy 
 
5.3   Subject Recruitment 

 
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There will be three available recruitment sources for the study.  The first will be existing tinnitus 
patients cared for by Otorhinolaryngology providers.  The second will be patients being referred 
for tinnitus to the Department of Otorhinolaryngology.  These patients will be identified by the 
appointment coordinators, consulting team, investigator, or study coordinator. The third group 
are people who have contacted the study team to participate in a tinnitus related research study 
at Mayo Clinic, after having seen a posting on ClinicalTrials.gov or the Mayo Clinic website. The 
study team may then contact the subject with a letter mentioning the prospective trial and will 
provide study team contact number to obtain more information. All members of the clinic team, 
including consultants, residents, audiologists, and nurses will be made aware of this study’s 
inclusion and exclusion criteria and will identify appropriate patients.  Consent to participate in 
the study will be obtained at the time of consultation.  Alternatively, subjects may be contacted 
by phone or video to review the inclusion and exclusion criteria, with the potential of being 
consented by phone or video and either signing the consent form electronically or by mail, if the 
subject can’t or doesn’t want to sign electronically.   
5.4   Withdrawal of Subjects 
 
Patients who are not able to be evaluated on the date of appointment or those who should 
choose to withdraw for any reason will have the option to withdraw at any time.   
 
 

 
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6   STUDY PROCEDURES 
6.1 Pre Visit Evaluation 
Eligible subjects will be identified for inclusion at the time of referral. The study coordinator or 
departmental research staff will confirm compliance with initial inclusion and exclusion criteria.  
Informed consent will then be obtained.  Then initial screening documentation, including THI, 
TFI, Tinnitus VAS-A and VAS-L, GAD7, GHQ, PHQ8, NEO-PI, and patient history will be 
reviewed.   
If the patient is being seen in the Otolaryngology clinic for an alternative chief complaint, but a 
screening review of systems identified significant tinnitus, one of the members of the research 
team will be available for screening consultation and may provide informed consent at that time.  
A copy of the consent form will be provided to the patient to keep, and a copy will be filed and 
stored.  Once enrolled, the THI, TFI, Tinnitus VAS-A and VAS-L, GAD7, GHQ, PHQ8 and NEO-
PI scores of the subject will be recorded by the research staff.   
If the patient is unable to schedule a Pre Visit Evaluation, consent may then be mailed (either 
via the postal service or electronically through PTRAX) to the patient.  The consenting provider 
will meet with the patient by phone or video visit and read through the consent form with the 
potential participant.  If desire to proceed, signed consent form will be returned either 
electronically or by mail and screening documentation will be provided to the patient.  The THI, 
TFI, Tinnitus VAS-A and VAS-L, and Pain VAS, GAD-7, PHQ-8, and/or the NEO-PI may be 
mailed or sent electronically to the subject after consent so they may do these eligibility 
screening surveys at home without making a trip to Mayo Clinic.  They will return these 
screening surveys which will be scored, and if the scores qualify, the subject will come in person 
for a clinical visit and the rest of the initial screening surveys, if they did not do the whole set at 
home.  
After eligibility is determined, subject will complete study questionnaires (THI, TFI, and Tinnitus 
VAS-A and VAS-L) at three separate time periods in conjunction with the first clinical visit.   
6.2   First Clinical Visit 
 
1. Patients enrolled in the study will proceed to Mayo Clinic Otorhinolaryngology 
Department for additional evaluation.  Candidate subjects will undergo a temporal bone 
CT, contrast enhanced head MRI, audiogram with immittance testing, pitch and level 
matching of tinnitus, and DPOAE and ABR testing prior to promontory stimulation. If 
during the course of the patient’s visit, any of the exclusion criteria are met, the patient 
will be withdrawn from the study, and will be notified of this as soon as possible. If the 
patient has already had a temporal bone CT and/or a head MRI, they do not need to get 
another for this study. 
a. The number and estimated length of each study visit 

 
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i. 5 visits in total.  The first visit would include a ~30 minute overview. The 
next visit would require ~2 min temporal bone CT, ~45 min MRI with 
contrast, ~45 min ABR, ~45 min audiogram and DPOAE, ~30-60 min of 
stimulation.  The next 2 visits would require ~30-60 min stimulation. The 
last visit would require ~20 min for tympanic membrane evaluation for 
residual perforation and ~45 min for audiogram. 
 
6.2.1   Transtympanic Cochlear Promontory Stimulation 
 
 
a. At the first, second and third clinical appointment, the promontory stimulation 
equipment (Cochlear Corporation Nucleus Promontory Stimulator Z10012®; 
Cochlear Corporation, Melbourne, Australia) will be used. The initial session of 
promontory stimulation will define optimal stimulation parameters (i.e., current 
level, and frequency), where maximal tinnitus suppression occurs with minimal or 
no auditory percept. Stimulus amplitude will be increased slowly to establish 
threshold and maximum acceptable loudness.  As an internal control function, 
testing will include a run of “on-off” simulations blinded to the subject, with patient 
blinded status to the “off” or “on” position of the stimulation machine.  After these 
parameters are established, the patient will complete the THI, TFI, and VAS 
immediately prior to stimulation, during stimulation, and following completion of 
stimulation at 10-minutes, 1-hour, 24-hours, 48-hours, and 1-week following 
completion of stimulation (or prior to the next scheduled session of promontory 
stimulation, whichever occurs sooner), in addition to the recall survey, which is 
completed after a time period of one week (or prior to the next scheduled session 
of promontory stimulation, whichever occurs sooner). In addition, pitch and level 
matching of tinnitus will be completed immediately prior to the first promontory 
stimulation session and after the last session. Each patient will undergo three 
successive treatments separated by 7 days (+14/- 2 days). Prior to each 
treatment, the patient will receive an audiogram and DPOAE testing to document 
interval safety. At the conclusion of the study, subjects will be asked about their 
willingness to undergo surgical implantation of a device capable of long-term 
scheduled or on-demand electrical stimulation for tinnitus suppression. 
b. The Cochlear Corporation Nucleus Promontory Stimulator Z10012 (Cochlear 
Corporation, Melbourne, Australia) will deliver stimulatory electric pulses. The 
stimulation will be delivered to the target sites using a transtympanic electrode 
kit, which contains a monopolar transtympanic needle electrode referenced to a 
surface electrode to be placed on the patient’s forehead. The tympanic 
membrane will be visualized with otomicroscopy with the patient in the supine 
position. Phenol will be applied to the tympanic membrane for local anesthesia. If 
residual irritation is perceived, EMLA cream will be used in the external auditory 
canal.  The transtympanic electrode needle will be guided through the external 
canal aiming for the posteroinferior quadrant of the tympanic membrane. The 
needle will be stabilized in the ear canal using cotton packing or hearing aid mold 
putty and adhesive tape. Initially, an electrode impedance test will be performed 

 
Page 12 of 13 
 
to validate proper placement and electrical contact of the electrodes. An indicator 
light will denote when impedances are not acceptable. If impedance values are 
not acceptable, a gentle repositioning of the proximal end of the needle electrode 
may be employed to ensure proper placement on the promontory. Otherwise, the 
needle electrode will be removed and reintroduced. Once proper electrical 
contact is validated, a calibration session to assess optimal stimulation 
parameters for the therapeutic session will be carried out using a ranged of 0 to 1 
mA for pulse frequencies 100 Hz, 800 Hz and 1600 Hz. For each stimulus 
frequency, current level will be gradually increased to determine the following 
perceptual parameters: 1) Detection threshold or minimum threshold: first 
detection of the electrical stimulus (tactile or audible) as reported by the patient. 
2. Maximum acceptable loudness level or discomfort level: when the applied 
current is perceived as loud but not uncomfortable.  3. The effective stimulation 
level will be determined to be 80% of the discomfort level or at minimum the 
minimum threshold level. The total duration of the electrical stimulation (at the 
optimal level) in each session will be ~30-60 minutes.  
6.2.2 ABR 
a. A threshold ABR using a 37.7 rate click stimulus will be used for auditory brainstem 
response testing. 
6.2.3 DPOAEs 
a. DPOAEs will be tested 1-10 kHz.  Presence of DPOAEs will be determined using the 
following criteria: 6 dB SNR; absolute level of >=-10 dB. 
 
6.3   Postprocedural appointment 
The primary investigator will visit with each patient one month after the three sequential 
electrical stimulation visits. The tympanic membrane will be evaluated for evidence of persistent 
perforation.  
 
6.4 Study Coordination 
When a prospective subject is identified by the appointment schedulers, consultants, 
audiologists or research team, the research team will be notified.  A member of the study team 
will provide information about the study to the subject and will serve as the point of contact for 
the subject.  A member of the study team will help organize the administration and receipt of 
surveys, as well as coordinate appointment visits.  They will allot for breaks in between separate 
tests for patient comfort.   
 
7   DATA COLLECTION AND ANALYSIS 
7.1   Data to Be Collected 

 
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Demographic data to be collected will include patient’s age, sex, medical comorbidities, current 
medications and medications taken within the last year, preoperative THI, TFI, Tinnitus VAS-A 
and VAS-L, GAD7, PHQ8, GHQ and NEO PI-R. 
 
 
The patient will complete the THI, TFI and Tinnitus VAS-A and VAS-L immediately prior to 
stimulation, during stimulation, and following completion of stimulation at 10-minutes, 1-hour, 
24-hours, 48-hours, and 1-week (or prior to the next scheduled session of promontory 
stimulation, whichever occurs sooner) following completion of stimulation.  
 
7.2 Data Analysis 
 
a Power Analysis 
Assuming the power was 80% and a one sided alpha of .05; we sought to determine a 
power analysis to detect a clinically significant decrease in tinnitus symptoms [3,12]. 
True Change in 
THI 
SD of Change 
of THI 
Sample Size 
 
 
Equality  
Superiority 
using 7 as 
bottom 
threshold 
Superiority using 5 as 
bottom threshold 
7 
10 
11 
 
156 
7 
15 
22 
 
350 
7 
20 
38 
 
619 
10 
10 
6 
71 
27 
10 
15 
12 
156 
58 
10 
20 
19 
277 
101 
15 
10 
4 
12 
8 
15 
15 
4 
24 
16 
15 
20 
6 
41 
27 
 
There are three different types of analysis used above to calculate sample size.  
The first analysis shown is an equality test which assesses whether the mean change in THI 
level is different from zero. This is the simplest power calculation and is usually associated with 
a t-test. In our research question, we would like to consider the procedure a success if the 
scores improve significantly by a certain amount. This test only examines that, if the true change 
is 7 (10), it is different from zero.  
The second two analyses seek to quantify the amount of change in THI we would like to 
consider clinically relevant. If we believe a clinically relevant change is 7 points on the THI scale 
we want to ensure that we have sufficient sample size to detect a mean change at or higher 
than 7. The final sample size column is less stringent in the mean we have to detect to consider 
the treatment a success, with requiring only a 5 point change to be clinically relevant (the 
threshold for not improving in the paper above).   

 
Page 14 of 13 
 
The power calculation suggests that if we believe our true mean change to be a 15 THI points 
with a SD of 15, a difference greater than or equal to 5 can be detected using 16 subjects, while 
if we want to detect a mean change greater than 7 we would need 24 subjects.  
b Data Analysis 
 
THI, TFI and Tinnitus VAS scores will be analyzed based on numeric change over time after 
each promontory stimulation procedure.  Data from the Audiograms / DPOAE will be assessed 
to ensure no baseline change in hearing has occurred as safety precautionary measures. 
 
The NEO PI will be evaluated to determine correlation between tinnitus improvement scores and 
baseline personality assessment. Results of the NEO PI will not be used to screen for enrollment. 
 
8   DATA HANDLING 
Data will be collected and handled in a manner to protect patient health information.  
 
Data extracted from the cochlear promontory stimulation monitoring system will be collected by 
the investigator. The data will then be extracted to a secure database on the Mayo Clinic server. 
Once the data has been transferred, the data will be deleted from the flash drive. Only the 
principal and co-investigators will have access to this data. Visit data will also be entered into 
this secure database. Access to the database will be restricted to research staff and will be 
unavailable to any third party.  
 
The Head Study Coordinator will be responsible for handling of protected health information 
according to the requirements of the Health Insurance Portability and Accountability Act of 1996 
(HIPAA). In accordance to this, a signed consent form by patient will be obtained that informs 
the subject of the following: 
• 
What protected health information (PHI) will be collected from subjects in this study 
• 
Who will have access to that information and why 
• 
Who will use or disclose that information 
• 
The rights of a research subject to revoke their authorization for use of their PHI.  
9   STUDY FUNDING 
Part of the funding for this study will be obtained via internal research funds within the 
Department of Otorhinolaryngology, Mayo Clinic, Rochester, Minnesota. 
 
Part of the funding for this study will be financed by the Peer Reviewed Medical Research 
Program (PRMRP) Clinical Trial Award through the Department of Defense. 
 
 
 
 
 
 
 

 
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10   REFERENCES 
 
 
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Head Neck Surg. 2014 Oct;151(2 Suppl):S1-S40. 
2. Tsai BS, Sweetow RW, Cheung SW. Audiometric asymmetry and tinnitus laterality. 
Laryngoscope. 2012 May;122(5):1148-53. 
3. Perez R, Shaul C, Vardi M, Muhanna N, Kileny PR, Sichel JY. Multiple electrostimulation 
treatments to the promontory for tinnitus. Otol Neurotol. 2015 Feb;36(2):366-72. 
4. Rubinstein JT, Tyler RS, Johnson A, Brown CJ. Electrical suppression of 
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APPENDIX A.  COCHLEAR PROMONTORY 
STIMULATION