Cochlear Implantation in Cases of Single-Sided Deafness
Phase: NA
Conditions: Unilateral Moderate to Profound Hearing Loss, Asymmetric Hearing Loss, Single-Sided Deafness (SSD)
Sponsor: University of North Carolina, Chapel Hill

 
Cochlear Implantation in Cases of Single-Sided Deafness 
 
 
 
NCT number NCT02203305 
Document Date 11/10/2015 
 
 
 

Cochlear Implantation in Cases of Single-Sided Deafness 
Protocol: Version 6.0, 11/10/2015 
 
I. 
Site Information: 
 
A. Investigators 
 
Margaret T Dillon, AuD (Principal Investigator and Sponsor) 
Assistant Professor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-966-5251 
Fax: 919-966-7941 
Email: mdillon@med.unc.edu 
 
Harold C Pillsbury III, MD, FACS (Co-Investigator) 
Professor 
Chair, Department of Otolaryngology/Head and Neck Surgery 
Executive Director, W Paul Biggers Carolina Children’s Communicative Disorders 
Program (CCCDP) 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-966-8926 
Fax: 919-966-7941 
Email: hcp@med.unc.edu 
 
Kevin Brown, MD, PhD (Co-Investigator) 
Associate Professor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-843-4820 
Fax: 919-966-7941    Email: kevin.d.brown@med.unc.edu 
 
Emily Buss, PhD (Co-Investigator) 
Professor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-843-1963 
Fax: 919-966-7941 
Email: ebuss@med.unc.edu 
 
 
 
 

 
 
English R King, AuD (Co-Investigator) 
Clinical Coordinator of Adult Cochlear Implants 
Department of Audiology 
UNC Health Care System 
101 Manning Drive,  
Chapel Hill, NC, 27514 
Tel: 919-490-3716 
Fax: 919-490-5818 
Email: erking@unch.unc.edu 
 
Ellen J Pearce, AuD (Co-Investigator) 
Clinical Audiologist 
Department of Audiology 
UNC Health Care System 
101 Manning Drive,  
Chapel Hill, NC, 27514 
Tel: 919-490-3716 
Fax: 919-490-5818 
Email: epearce@unch.unc.edu 
 
Meredith L Anderson, AuD (Co-Investigator) 
Research Instructor 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-966-5251 
Fax: 919-966-7941  
Email: meredith_anderson@med.unc.edu 
 
Andrea L Bucker, AuD (Co-Investigator) 
Clinical Audiologist 
Department of Audiology 
UNC Health Care System 
101 Manning Drive, 
Chapel Hill, NC, 27514 
Tel: 919-490-3716 
Fax: 919-490-5818 
 
Email: Andrea.Bucker@unchealth.unc.edu 
 
Sarah McCarthy, AuD (Co-Investigator) 
Clinical Audiologist 
Department of Audiology 
UNC Health Care System 
101 Manning Drive 
Chapel Hill, NC, 27514 
Tel: 919-490-3716 
Fax: 919-490-5818 
 
Email: Sarah.McCarthy@unchealth.unc.edu 
 
 

 
 
B. Speech Language Pathologists 
 
Hannah R Eskridge, MSP (Speech Language Pathologist) 
Program Director, Center for Acquisition of Spoken Language Through Listening 
Enrichment 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-419-1449 
Fax: 919-966-7941 
Email: hruark@unch.unc.edu 
 
Lillian Henderson, MSP (Speech Language Pathologist) 
Lead Speech and Language Pathologist 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-419-1449 
Fax: 919-966-7941 
Email: lhenders@unch.unc.edu 
 
Maegan Evans, PhD (Speech Language Pathologist) 
Pediatric Speech and Language Pathologist 
Department of Otolaryngology/Head and Neck Surgery 
University of North Carolina at Chapel Hill 
170 Manning Drive, Physician’s Office Building G190, CB 7070 
Chapel Hill, NC, 27599-7070 
Tel: 919-419-1449 
Fax: 919-966-7941 
Email: mkevans@unch.unc.edu 
 
 
 
C. IRB 
 
 
University of North Carolina Biomedical Institutional Review Board 
 
Co-Chairs: David Weber, Doug Mann, Kim Brownley, Herbert Patterson 
 
Medical School Building 52 
 
University of North Carolina at Chapel Hill 
 
105 Mason Farm Road, Chapel Hill, NC, 27599-7097 
 
Tel: 919-966-3113 
Fax: 919-966-7879 
 
 
 

II. 
Introduction 
 
Single-sided deafness (SSD) can be defined as moderate-to-profound sensorineural hearing loss with 
limited speech perception benefit in one ear and normal hearing in the contralateral ear. Though one 
ear is within the normal hearing limits, SSD results in reduced speech perception in noise (Welsh et 
al, 2004; Rothpletz, Wightman & Kistler, 2012), variable abilities on localization tasks (Slattery & 
Middlebrooks, 1994), increased report of hearing handicap (Iwasaki et al, 2013), and reduced quality 
of life (Wie, Pripp & Tvete, 2010). 
 
This patient population cannot utilize conventional amplification due to the severity of the hearing 
loss and poor speech discrimination abilities in the affected ear. Current treatment options include: 
contralateral routing of the signal (CROS) hearing aids, and bone-conduction devices. A CROS 
hearing aid is a two-part system that includes a microphone/transmitter on the affected ear and a 
receiver on the normal hearing ear. The microphone/transmitter sends the acoustic signal from the 
affected ear to the receiver, which is presented to the normal hearing ear. Bone-conduction devices 
utilize a percutaneous, implanted titanium abutment to send the acoustic signal from the affected side 
to the normal hearing ear via vibrations.  The goal of both of these technologies is to send the signal 
from the affected side to the normal hearing side, thereby leaving the patient in a unilateral listening 
condition. 
 
Though CROS hearing aids and bone-conduction devices provide the patient with auditory 
information from both sides to the better hearing ear, the ability to use binaural cues for speech 
perception in noise is variable (Kunst et al, 2007), and localization abilities have been found to be at 
chance (Bosman et al, 2003; Hol et al, 2010). For instance, Bosman et al (2003) compared three 
listening conditions in SSD subjects: unaided, CROS hearing aid and bone-conduction hearing aid. 
Subjects were allowed 4 weeks of listening experience for habituation with the CROS and bone-
conduction hearing aids. Subjects reportedly experienced no difference in localization abilities 
between each condition, indicating the current technology available to this population could not 
improve localization abilities over the unaided condition. 
 
It is of interest whether cochlear implantation of the affected ear would benefit the SSD 
population. A cochlear implant is a two-part system, including the internal electrode array 
and external speech processor. The internal electrode array is surgically implanted into the 
affected cochlea. The external speech processor receives sounds and transmits this signal to 
the internal portion. The electrode array presents the acoustic signal via electrical pulses 
within the cochlea, which is interpreted by the brain as sound. A steady growth in speech 
perception acquisition has been reported in conventional cochlear implant subjects up to 6-12 
months of listening experience with the external speech processor (Pelizzone, Cosendai, & 
Tinembart, 1999). Presumably, cochlear implantation may provide the SSD population 
improvements in speech perception in the affected ear, which cannot benefit from 
appropriately fit hearing aids. Cochlear implantation may provide a benefit over current 
treatment options in the SSD population, as it stimulates the auditory pathway on the affected 

side, thus allowing for ipsilateral representation of acoustic signals arriving to each ear 
independently.  
 
Bilateral stimulation of the auditory system has been shown to improve speech perception in 
spatially-separated noise and localization abilities. These gains have been reported in 
bilateral cochlear implant recipients (van Hoesel & Tyler, 2003; Nopp, Schleich & D’Haese, 
2004; Grantham et al, 2007).  For instance, Grantham et al (2007) assessed the localization 
abilities of bilateral cochlear implant subjects at approximately 5 months of listening 
experience and then again 10 months later. The authors reported localization abilities did not 
differ significantly between these two intervals, indicating the ability to use binaural cues for 
improved localization developed after even limited listening experience with the external 
speech processors. Considering this subject population has bilateral hearing impairment, it is 
of interest whether the performance acquisition would be different in an SSD case with 
cochlear implantation since there is the added benefit of a normal hearing ear. 
 
Cochlear implantation has been reported as a viable treatment option in cases of unilateral hearing 
loss, including sudden sensorineural hearing loss (Firszt et al, 2012), and severe tinnitus (Vermiere & 
Van de Heyning, 2009; Van de Heyning et al, 2008). Further, cochlear implantation has been shown 
to offer superior speech perception in noise, localization abilities, and subjective report in SSD cases 
as compared to CROS hearing aids and bone-conduction devices (Arndt et al, 2011). The limitation to 
this comparison, however, was the subjects had limited listening experience with the alternative 
treatment options (i.e. CROS hearing aids or bone-conduction device). Though other studies reported 
no difference in abilities with these technologies after 4 weeks of listening experience (Bosman et al, 
2003), long-term duration of listening experience may influence speech perception and localization 
abilities. Considering this, a control condition of long-term users of current treatment options (i.e. 
bone-conduction devices) may provide a more accurate comparison with SSD cochlear implant 
recipients. 
 
The primary goal of this project is to determine whether subjects with SSD experience an 
improvement in speech perception, localization, and quality of life with a cochlear implant as 
compared to an unaided listening condition. Secondary aims include: 1) a comparison of 
speech perception, localization, and quality of life outcomes in the study population to a SSD 
control group with long-term listening experience with a current treatment option (i.e. bone-
conduction device), and 2) a within-subject comparison of speech perception and localization 
abilities with cochlear implantation versus the bone-conduction test device. 
 
III. 
Objectives 
 
A. The primary purpose of this feasibility study is to demonstrate the effectiveness of 
cochlear implantation in subjects with SSD 
1. Postoperative results will be evaluated with speech perception measures, localization 
tasks, and subjective reports 
 

B. Compare outcomes of cochlear implantation to that of current treatment options (i.e. 
bone-conduction devices) for SSD cases 
1. Compare speech perception, localization, and subjective outcomes to a control group 
of implantable bone-conduction device recipients 
2. Assess cochlear implant subjects with a bone-conduction test device and/or previous 
BAHA device at the preoperative and 12 month follow-up intervals  
a. Comparison of individual subject speech perception and localization abilities 
between the cochlear implant and bone-conduction device 
 
IV. 
Definitions 
 
Adjusted Constant Error: the rms deviation of the mean responses from the diagonal, computed 
after compensating for bias. This procedure reduces the bias when evaluating the relationship 
between the average response on the azimuth and signal source on the azimuth. 
 
Bimodal: Cochlear implant in one ear and a conventional hearing aid in the contralateral ear 
 
Bone-Conduction Device: A device on the poorer hearing ear that picks up the acoustic signal on the 
effected side and transmits to the better hearing ear via vibrations through the skull. This is 
accomplished by either securing the oscillator to the head with a headband or via a percutaneous, 
implanted titanium abutment.  
 
Cochlear Implant (CI): A two-part system, including the internal electrode array and external 
speech processor that stimulates the auditory pathway on the effected side. The internal electrode 
array is surgically implanted into the affected cochlea. The external speech processor receives sounds 
and transmits this signal to the internal portion. The electrode array presents the acoustic signal via 
electrical pulses within the cochlear space, which is interpreted by the brain as sound. 
 
Constant Error: the rms deviation of the average responses from the source positions 
 
Contralateral Routing of Signal (CROS) Hearing Aids: A two-part system consisting of a 
transmitter microphone on the deafened ear and a receiver on the normal hearing ear. The transmitter 
sends the signal from the deafened ear to the normal hearing ear. The auditory pathway on the normal 
hearing ear receives the sound. 
 
Interaural Level Difference (ILD): The difference in sound level between the two ears, dependent 
on the location of the sound source and the orientation of the head. This binaural cue is typically 
dominated by high frequencies. 
 

Interaural Timing Difference (ITD): The difference in the time a sound arrives to one ear as 
compared to the other, dependent on the location of the sound source and the orientation of the head. 
This binaural cue is typically dominated by low frequencies.  
 
Pure Tone Average (PTA): The average threshold (dB HL) from 500, 1000, and 2000 Hz 
 
Random Error: the standard deviation of responses at each signal source position, averaged across 
all potential signal sources 
 
Root-Mean-Square (rms) Error: The difference between the location on the azimuth of the sound 
source and the subject’s response on each trial for the localization task 
 
Single-Sided Deafness (SSD): Severe-to-profound sensorineural hearing loss with limited speech 
perception in one ear and a normal to mild hearing in the contralateral ear 
 
V. 
Investigational Device 
 
A. Subjects will be implanted with the commercially available MED-EL CONCERT 
cochlear implant with the standard electrode array (MED-EL Corporation, Innsbruck, 
Austria). The device consists of a stimulator, a coil with a magnet within its center, a 
reference electrode, an EAP reference electrode and an active electrode permanently 
attached to the stimulator. The electrode is made of medical grade silicone, platinum 
(electrode contacts) and platinum/iridium (90/10) wires and nitinol. 
 
The purpose of the device is perception of environmental sound and potential for 
improvement in communication abilities. 
 
For the adult population, the MED-EL CONCERT cochlear implant is indicated for those 
18 years of age or older, who have bilateral sensorineural hearing impairment and obtain 
limited benefit from appropriately fitted binaural hearing aids.  
 
The standard electrode array is 31.5 mm long, with 12 pairs of contacts spaced over 26.4 
mm with 2.4 mm spacing between each contact pair. The electrode’s length allows 
insertion into the scala tympani and stimulation of the cochlear canal to the fullest extent 
possible. The array features a marker ring 31.5 mm from the apex that is used to seal the 
cochleostomy and to indicate maximum electrode insertion. The diameter of the array 
increases to 1.3 mm at the proximal thicker part of array just before the marker ring. 
 
Subjects will be fit with the Opus 2 speech processor. The Opus 2 speech processor is an 
external component of the MAESTRO Cochlear Implant System and is indicated for use 
on patients who have been implanted with a MED-EL cochlear implant.  The Opus 2 

audio processor consists of the control unit with the earhook attached, the battery pack 
frame and cover, the connecting piece, the coil and the coil cable.  The audio processor 
uses batteries that provide sufficient power for both the external and the implanted 
electronics. 
 
The MAESTRO 6.0 Fitting Software will be used to program the Opus 2 speech 
processor. The MAESTRO 6.0 software, which is used for different intraoperative and 
postoperative purposes for the MED-EL Cochlear Implant System. Currently, it contains 
the implant Telemetry and Fitting of the OPUS 1 or OPUS 2 processor, ART (Auditory 
nerve Response Telemetry) and ESRT (Electrically Evoked Stapedius Reflex Threshold), 
and Audiogram functions.  The MAESTRO software is an external component of the 
MED-EL Cochlear Implant System and is intended to be used in a clinical or office 
environment by persons adequately skilled and trained to perform all intended tasks and 
with patients who received one of the intended MED-EL cochlear implants. 
 
VI. 
Study Duration 
 
A. Enrollment Period 
1. 4 years 
 
B. Study Timeline 
1. Cochlear implant subjects 
a. Each subject’s involvement will last approximately 1.5 years, including: 
candidacy evaluation, preoperative evaluation, surgical procedure, initial 
activation of the external speech processor, and post-initial activation evaluations 
(1, 3, 6, 9 and 12-months post-initial activation) 
 
2. Bone-conduction device control group 
a. One evaluation interval to complete the test battery outlined in section VII.D.  
 
C. Study Endpoint 
1. Cochlear implant subjects 
a. The 12-months post-initial activation interval 
 
2. Bone-conduction device control group 
a. Completion of the test battery (1 interval) defined in section VII.D. 
 
 
 
VII. 
Methods 
 
All procedures will be conducted by UNC investigators, including board-certified otologists, 
audiologists, and speech-language pathologists. Fully informed consent will be obtained from all 
subjects. 

 
A. Participants: CI subjects 
Subjects must meet the following inclusion criteria and not exhibit any of the exclusion 
criteria. 
 
1. Inclusion Criteria 
a. Unilateral moderate-to-profound sensorineural hearing loss 
i. 
Unaided residual hearing thresholds measured from 250-8000 Hz (PTA ≥70 
dB HL in the ear to be implanted) 
ii. 
Normal to mild residual hearing thresholds from 250-8000 Hz in the 
contralateral ear (≤35 dB HL at each frequency, 250-8000 Hz) 
b. Greater than or equal to 18 years of age at implantation 
c. Duration of moderate-to-profound sensorineural hearing loss less than or equal to 
5 years 
i. 
Either reported by subject or documented in previous audiograms 
ii. 
Can be less than or equal to 10 years if the subject consistently utilized 
hearing technology (such as a bone conduction device or conventional 
hearing aid) within the past 5 years 
d. Previous experience with a current treatment option for SSD, including a 
conventional hearing aid, bone-conduction device, or CROS/BICROS technology. 
i. 
At least one month of listening experience with device 
ii. 
Dissatisfaction with and/or discontinued use of current treatment option due 
to: insufficient gain, poor sound quality, and/or lack of perceived benefit. 
e. Aided word recognition in the ear to be implanted of 60% or less as measured 
with CNC words (50-word list) 
i. 
When listening with an appropriately fit hearing aid and masking applied to 
the contralateral ear 
ii. 
Aided testing will be conducted in a sound-proof booth with the subject 
seated 1 meter from the sound source, facing 0° azimuth. Recorded materials 
will be presented at 60 dB SPL. 
iii. 
The hearing aid output will be measured using NAL-NL1 targets. 
f. Realistic expectations: a verbal acknowledgement of the potential benefits and risks, 
and postoperative variation in performance. For instance, cochlear implantation will not 
restore normal hearing 
g. Willing to obtain recommended meningitis vaccinations per CDC 
recommendations 
h. No reported cognitive issues  
i. 
Pass the Mini Mental State Examination (MMSE) screener 
i. Able and willing to comply with study requirements, including travel to 
investigational site and study-related activities 
 
2. Exclusion Criteria 
a. Non-native English speaker 
i. 
Speech perception materials are presented in English 
b. Conductive hearing loss in either ear 

c. Compromised auditory nerve, including those with a history of vestibular 
schwannoma 
d. Ossification  
e. Inability to participate in follow-up procedures (i.e., unwillingness, geographic 
location) 
f. History of meningitis, autoimmune disease, or any medical condition that 
contraindicate middle or inner ear surgery or anesthesia 
g. Meniere’s disease with intractable vertigo 
h. Trauma that precludes inner ear surgery 
i. Case of sudden sensorineural hearing loss that has not been first evaluated by a 
physician  
j. Pregnancy 
i. 
Subjects who are pregnant or become pregnant prior to surgery are excluded 
due to the potential risk of anesthesia to an unborn child. 
a. Subjects who become pregnant after surgery may continue to participate in 
study procedures 
k. Tinnitus as the primary purpose for seeking cochlear implantation 
l. Subject obtains a severe or catastrophic score on the Tinnitus Handicap Inventory 
(Newman, Jacobson & Spitzer, 1996). 
 
3. Enrollment 
a. This study seeks to enroll twenty (20) subjects 
 
 
B. Participants: Control group 
Subjects must meet the following inclusion criteria and not exhibit any of the exclusion 
criteria. 
 
1. Inclusion Criteria 
a. Unilateral moderate-to-profound sensorineural hearing loss 
i. 
Unaided residual hearing thresholds from 250-8000 Hz (PTA ≥70 dB HL on 
the implanted side) 
ii. 
Normal to mild residual hearing thresholds from 250-8000 Hz in the 
contralateral ear ≤35 dB HL at each frequency, 250-8000 Hz 
b. Recipient of bone-conduction device on affected side  
i. 
Recipient of the Bone-Anchored Hearing Aid (BAHA) 
a. Either the Cochlear BAHA Connect or Attract system 
ii. 
At least 12 months of listening experience with the BAHA system 
c. Greater than or equal to 18 years of age  
d. Duration of moderate-to-profound sensorineural hearing loss less than or equal to 
5 years at time of implantation with bone-conduction device (BAHA) 
i. 
Either reported by the subject or documented in previous audiograms 
e. Willingness to participate in test battery 
 
2. Exclusion Criteria 
a. Non-native English speaker 

i. 
Speech perception materials are presented in English 
b. Conductive hearing loss in either ear 
c. Compromised auditory nerve, including those with a history of vestibular 
schwannoma 
d. Inability to participate in test battery 
 
3. Enrollment 
a. This study seeks to enroll at least 10 subjects in the control group 
 
C. Timeline 
Appendix A graphically depicts the timeline and associated measures 
 
The Candidacy Evaluation and Preoperative Evaluation can either occur during the same 
visit or two different visits. 
 
1. Candidacy Evaluation. This interval may overlap with the Preoperative Evaluation 
interval. 
 
a. Audiologic Evaluation 
i. 
Unaided air- and bone-conduction thresholds in both ears 
a. Air-conduction assessed with inserts 
ii. 
Unaided word recognition in both ears 
a. Measured with recorded CNC words (50-word list) 
b. Masking provided when appropriate 
iii. 
Tympanometry in both ears 
iv. 
Aided word recognition in the affected ear 
a. Measured with recorded CNC words (50-word list) 
b. Masking applied to the contralateral ear 
v. 
Completion of the Tinnitus Handicap Inventory 
vi. 
Determine if potential subject meets candidacy criteria 
 
b. Medical Evaluation 
i. 
Determine if potential subject is healthy enough to undergo cochlear 
implantation 
ii. 
Associated imaging studies 
a. This is standard of care for these patient populations 
b. May also be completed at Preoperative Evaluation 
iii. 
Discussion of alternative treatment options  
iv. 
Determine if potential subject meets candidacy criteria 
 
c. Informed Consent 
i. 
Review and discussion of consent form 
ii. 
Provide time for subject to review consent form and ask questions 
iii. 
Provide subject with a signed copy of the completed consent form 
 

2. Preoperative Evaluation. This interval may overlap with the Candidacy Evaluation 
interval.  
 
The Preoperative Evaluation will be completed within 6 months of the surgery date. 
 
a. Audiologic Evaluation 
i. 
Obtain a case history, including but not limited to: 
a. Onset of hearing loss 
b. Progression to moderate-to-profound sensorineural hearing loss 
c. Suspected etiology of hearing loss 
ii. 
Unaided air- and bone-conduction thresholds in both ears 
a. Air-conduction assessed with insert phones 
iii. 
Unaided word recognition with CNC words in both ears 
a. Measured with recorded CNC words (50-word list) 
b. Masking provided when appropriate 
iv. 
Tympanometry in both ears 
v. 
Subjects will complete the test battery detailed in section VII.D. 
a. Two listening conditions:  
i. 
unaided  
ii. 
bone-conduction test device or BAHA 
a. The bone-conduction test device will be the Cochlear BAHA 
Intenso on a headband 
b. If the subject has a BAHA (Cochlear Connect or Attract system) 
then her or she may use the external processor associated with 
that system.  
b. Subjects who listen with a hearing aid in the contralateral ear may utilize 
this technology during this listening condition 
i. 
Hearing aid output will be measured using the NAL-NL1 targets 
vi. 
Counseling on cochlear implant external technology, realistic expectations, 
study test battery, and postoperative timeline 
 
b. Medical Evaluation 
i. 
Subjects will undergo a medical assessment and review of medical history 
ii. 
Associated imaging studies 
a. This is standard of care for these patient populations 
b. May have been completed at Candidacy Evaluation 
iii. 
Counseling on cochlear implantation surgical procedure and postoperative 
considerations, including MRI limitations due to internal magnet 
a. MED-EL Concert device approved for 0.2 or 1.5 Tesla  
 
3. Surgery: Cochlear Implantation 
 
Risk factors associated with cochlear implantation are listed in Section XI “Risk 
Analysis.”  
 

All surgical procedures will take place at the UNC Memorial Hospital or UNC 
Ambulatory Care Center (ACC) operating rooms. All procedures will be completed 
by board-certified otologists. 
 
4. Postoperative Evaluations 
a. Initial Follow-Up (approximately 1-2 weeks postoperatively) 
 
i. 
Medical Evaluation 
a. This is standard of care 
b. Subject will be seen by the physician  
 
ii. 
Audiologic Evaluation 
a. Unaided thresholds  
i. 
Air-conduction assessed with an insert phone in the contralateral ear 
ii. 
Bone-conduction thresholds assessed in the surgical ear 
 
b. Initial Activation of External Speech Processor (approximately 2-4 weeks 
postoperatively)  
i. 
Unaided air and bone conduction thresholds 
a. Air-conduction assessed with insert phones 
ii. 
Unaided word recognition with CNC words in both ears 
a. Measured with recorded CNC words (50-word list) 
b. Masking provided when appropriate 
iii. 
Initial activation of external speech processor 
a. Subjects will be fit with the commercially available MED-EL Opus 2 
external speech processor (MED-EL Corporation, Innsbruck, Austria), 
and/or alternative external speech processor. Speech perception and 
localization measures at follow-up intervals will be conducted with the 
subject listening with the Opus 2 external speech processor for the aided 
conditions. 
b. Mapping will be completed by board-certified audiologists. Mapping 
procedures will be similar to conventional cochlear implant recipients.  
iv. 
Counseling on the external device and use 
 
c. One-Month Post-Initial Activation  
i. 
Completion of test battery listed in VII.D. 
ii. 
Speech perception assessed with the cochlear implant on and contralateral ear 
masked 
a. CNC words 
iii. 
Mapping of the external speech processor 
 
d. Three-Months Post-Initial Activation  
i. 
Completion of test battery listed in VII.D. 
ii. 
Speech perception assessed with the cochlear implant on and contralateral ear 
masked 
a. CNC words 

iii. 
Mapping of the external speech processor 
 
e. Six-Months Post-Initial Activation  
i. 
Completion of test battery listed in VII.D. 
ii. 
Speech perception assessed with the cochlear implant on and contralateral ear 
masked 
a. CNC words 
iii. 
Mapping of the external speech processor 
 
f. Nine-Months Post-Initial Activation 
i. 
Completion of test battery listed in VII.D. 
ii. 
Speech perception with the cochlear implant on and contralateral ear masked 
a. CNC words 
iii. 
Mapping of the external speech processor 
 
g. Twelve-Months Post-Initial Activation (study endpoint) 
i. 
Completion of test battery listed in VII.D. 
a. Additional listening condition: bone-conduction test device or BAHA 
ii. 
Speech perception with the cochlear implant on and the contralateral ear 
masked 
a. CNC words 
iii. 
Mapping of the external speech processor 
 
 
D. Test Battery 
The following test battery will be completed at each assessment interval (preoperative, and 1, 3, 
6, 9 and 12 months postoperatively). All assessment and mapping will be conducted at the 
Carolina Crossing research lab by a board-certified audiologist.  
 
1. Unaided Diagnostic Assessment 
 
a. Air-conduction thresholds in both ears  
i. 
Air-conduction assessed with insert phones 
ii. 
Assess bone-conduction thresholds if there is a PTA shift of >15 dB as 
compared to the previous interval 
 
2. Tympanometry for each ear 
 
3. Sound Field Measures 
The Carolina Crossing research lab features a 180° arc with 11 speakers spaced 18° 
apart. This arc will be utilized during the speech perception and localization 
measures. 
 
Postoperative aided sound field assessment will be completed with the subject 
listening with the Opus 2 speech processor. 

 
Subjects who utilize a hearing aid in the contralateral ear may continue to use this 
technology during the sound field test conditions where the contralateral ear remains 
open. Hearing aid output will be measured using NAL-NL1 targets. 
 
a. Aided thresholds with the external speech processor on will be measured using 
pulsed, warble tones 
i. 
Frequencies assessed: 250-8000 Hz, including all inter-octaves 
ii. 
Masking presented to the contralateral ear 
 
b. Speech Perception Measures 
Recorded materials will be presented at 60 dB SPL. 
 
i. 
Speech Perception in Quiet 
a. Listening condition 
i. 
Speech 0° azimuth 
b. Speech perception materials 
i. 
CNC words  
ii. 
AzBio sentences 
 
ii. 
Speech Perception in Noise 
a. Listening conditions 
i. 
Speech and noise 0° azimuth 
ii. 
Speech 0° azimuth and noise to implanted side 
iii. 
Speech 0° azimuth and noise to contralateral ear 
b. Speech perception materials 
i. 
AzBio sentences 
a. If >50% at SNR+10, then SNR+5 
b. If >50% at SNR+5, then SNR+0 
ii. 
BKB-SIN sentences with adaptive SNR 
 
iii. 
Listening Conditions 
a. Cochlear implant speech processor off  
i. 
Contralateral ear only 
b. Cochlear implant speech processor on 
i. 
Cochlear implant + contralateral ear 
 
c. Localization 
i. 
The stimulus is a 200-ms speech-shaped noise, presented at 70-dB SPL from 
one of the 11 speakers (evenly spaced -180 to 180 degrees), selected at 
random 
ii. 
The intensity level for each stimulus presentation will be randomly varied 
(10 dB around 70 dB SPL)  
iii. 
The listener will be facing the center speaker during stimulus presentation.  
The task is to identify the source of the noise.  No feedback is provided. 
iv. 
Listening Conditions 

a. Cochlear implant speech processor off  
i. 
Contralateral ear only 
b. Cochlear implant speech processor on 
i. 
Cochlear implant + contralateral ear 
 
4. Subjective questionnaires 
a. Speech, Spatial and Qualities of Hearing Scale (SSQ), Gatehouse & Noble (2004) 
b. Abbreviated Profile of Hearing Aid Benefit (APHAB), Cox & Alexander (1995) 
c. Tinnitus Handicap Inventory, Newman, Jacobson & Spitzer (1996) 
 
E. Aural Rehabilitation 
1. Subjects will participate in two aural rehabilitation sessions with a board-certified 
speech-language pathologist. One session will be after the initial activation of the 
external speech processor. This will occur either on the same day as the initial 
activation or within the first 2 weeks of listening experience. The second session will 
be scheduled in conjunction with the 1-month post-initial activation interval.  
 
VIII. 
Proposed Claims 
 
A. Demonstrate the effectiveness of cochlear implantation in SSD subjects  
 
1. Demonstrate an improvement in speech perception abilities, localization, and/or 
subjective benefit in an aided (cochlear implant on) versus an unaided (cochlear 
implant off) condition 
 
B. Cochlear implantation provides similar or superior speech perception, localization, and/or 
quality of life as compared to that found with bone-conduction devices 
 
1. Comparison with control group performance 
2. Comparison within subject when listening with bone-conduction test device 
 
IX. 
Statistical Analysis 
 
A. Descriptive summaries will be provided for the following: subject demographics, and 
frequency of major and minor complications/adverse events. 
 
B. A single-subject design will be utilized, where each subject serves as his or her own 
control, for analysis of objective and subjective results. A single-subject design was 
chosen in order to accommodate the heterogeneity that is well known to characterize 
auditory prosthesis research. Repeated-measures ANOVA will be calculated with a p-
value of ≤ 0.05 for statistical significance. Statistical analysis will be conducted with 
SPSS software. 
 
1. Comparison of aided speech perception performance on word and sentence materials 
in the post-initial activation intervals to evaluate trends over time 

a. Comparison of the difference between the aided and unaided conditions at each 
follow-up interval 
 
2. Comparison of localization abilities in the post-initial activation intervals  
a. Comparison of the difference between the aided and unaided conditions for each 
follow-up interval 
b. Compute the overall rms error, random error, constant error, and adjusted constant 
error, as described by Grantham et al (2007) 
 
3. Comparison of subjective report scores in the post-initial activation intervals 
 
C. The incidence of interference between ears will be assessed by comparing the speech 
perception performance in the 0° azimuth conditions for the contralateral ear only versus 
cochlear implant + contralateral ear conditions for each subject, as well as the 
individual’s subjective report. 
 
A sample size for the cochlear implant recipient cohort of 20 subjects was selected due to known 
variability in conventional cochlear implant recipient outcomes and to allow for possible dropouts 
(approximately 20%). A comparable study, Hansen, Gantz & Dunn (2013) evaluated 29 cochlear 
implant subjects with SSD, which included etiologies of sudden sensorineural hearing loss, Meniere’s 
disease, and vestibular schwannoma. Authors reported a high degree of variability in their sample. 
This project will not enroll all of the etiologies included in the Hansen, Gantz & Dunn (2013) analysis 
(such as, Meniere’s Disease with intractable vertigo or history of vestibular schwannoma), therefore a 
smaller sample size was selected. The inclusion/exclusion criteria associated with this study, as 
compared to the heterogeneity of the Hansen, Gantz, & Dunn (2013) subject sample, will allow for 
more generalized comments about subjective and objective outcomes of cochlear implantation in 
cases of SSD. 
 
If needed, statistical consultation will be sought from the North Carolina Translational and Clinical 
Sciences Institute (TraCS) or UNC Odum Institute. 
 
X. 
Endpoints 
 
A. Safety endpoint 
1. The primary safety endpoint is the evaluation of Adverse Events. All Adverse Events 
will be reported to the UNC IRB. If the UNC IRB or study investigators deem an 
Adverse Event unacceptable, then this would result in termination of the study. 
 
B. Primary effectiveness endpoint 
1. The primary effectiveness endpoint is the comparison of speech perception, 
localization abilities and/or subjective report when the cochlear implant is on versus 
off. 
 
XI. 
Risk Analysis 

 
A. Potential risks 
 
The following are risks associated with the MED-EL Concert implant, which is also 
included in the device description: 
 
1. Loss of residual hearing 
2. Increased vertigo 
3. Delay of healing of the scar 
4. Impairment of the sense of taste 
5. Potential for swallowing difficulties 
6. Numbness 
7. Increased tinnitus 
8. Stimulation of the facial nerve 
9. Temporary pain and uncomfortable sounds during stimulation 
 
The following are potential risks the subject may experience related to the study 
procedure: 
 
1. Surgical 
a. Facial nerve injury 
i. 
Facial nerve monitoring is conducted during the surgical procedure  
b. Infection 
i. 
All subjects will be counseled regarding bacterial meningitis and 
recommended vaccinations 
c. Bleeding 
d. Cerebrospinal fluid (CSF) leak 
e. Pain 
f. Scarring 
 
2. Postoperative 
a. Swelling around the incision and/or coil site 
b. Pain 
c. Reduced or loss of pinna sensitivity on the surgical side 
i. 
Typically resolves 1-2 months postoperatively 
d. The cochlear implant may not provide any auditory stimulation 
e. The cochlear implant may provide auditory stimulation, but with a sound quality 
too poor to aid in the perception of speech 
f. The cochlear implant may provide auditory stimulation, but with a sound quality 
too poor to aid in localization 
g. Pain associated with the coil and/or placement of the external speech processor on 
the subject’s ear 
h. Movement of the internal receiver 
i. Discomfort from electric stimulation 
j. Facial nerve stimulation 
k. Headache 

l. Dizziness 
m. Altered taste (i.e. reports of metallic tastes on the same side of the tongue as the 
surgical ear) 
n. Fatigue during follow-up assessment (completion of the test battery and/or 
mapping) 
o. The internal device may fail, requiring revision cochlear implantation 
p. The sound from the cochlear implant may interfere with the better hearing ear.  
 
B. Risk Mitigation 
1. Current hearing device options, including CROS hearing aids and bone-conduction 
devices, would still be available to the subject in the future if the subject does not 
benefit from the cochlear implant or elects to no longer use the cochlear implant. 
a. The test battery includes a listening condition to assess the monaural performance 
of the contralateral ear. Interference of the cochlear implant on the performance of 
the contralateral ear can be evaluated by comparing the contralateral ear only 
condition to the cochlear implant + contralateral ear conditions when tested at 0° 
azimuth, as well as, review the subjective benefit via the subjective questionnaires. 
If interference is found to impact speech perception and subjective benefit, the 
subject may elect to discontinue use of the cochlear implant and would still have 
access to currently approved technologies for SSD. 
2. Magnet strength will be assessed at each interval to ensure comfort at the coil site. 
3. Reports of pain from the external speech processor placement will be addressed by 
different wearing options (i.e. moleskin between the external speech processor and 
the subject’s ear, or different battery-wearing options to lighten weight on the pinna). 
4. Mapping will be conducted at each post-initial activation interval to improve 
audibility and comfort of the sound quality from electric stimulation. 
5. The MED-EL cochlear implant has MRI limitations*. Subjects may have CT scans or 
x-ray imaging postoperatively when warranted. 
a. *The MED-EL CONCERT cochlear implant is approved for MRI of 0.2 or 1.5 
Tesla 
6. An otologist will conduct medical follow-up evaluations at the 6 and 12-month 
intervals, which is standard of care for cochlear implant recipients. 
7. Age appropriate vaccinations per the CDC recommendations will be completed by 
each subject prior to implantation. Subjects will be counseled regarding meningitis 
vaccinations and directed where to obtain them by their implanting physician. 
 
XII. 
Potential Benefits 
 
A. Improvement in speech perception abilities in noise with the cochlear implant due to 
utilization of auditory cues from both ears. 
 
B. Improvement in localization abilities with the cochlear implant due to utilization of 
auditory cues from both ears. 
 
C. Improvement in subjective benefit with the cochlear implant as compared to preoperative 
performance.  

 
The potential benefits of cochlear implantation in cases of SSD are suspected to outweigh the risks 
listed in Section XI.A. The study sample will include subjects with previous history with current 
hearing technology options for SSD, who are dissatisfied with this technology and/or have 
discontinued use of the technology. This sample is similar to those in previously published reports 
who have benefited from cochlear implantation.  
 
This study also includes a comparison to a currently approved technology option for SSD, bone-
conduction technology. This comparison will be used to assess outcomes between technologies, but 
also to determine whether individual subjects experience differences in performance between the two 
technologies. The risks associated with cochlear implantation in this population are also reduced 
considering subjects may continue to use currently approved technologies for SSD if they do not 
obtain subjective and objective improvements from cochlear implantation. 
 
XIII. 
Adverse Events 
 
A. Anticipated versus Unanticipated Events 
1. Anticipated Events: those events described as potential risks (section XI.A.) of the 
protocol 
 
2. Unanticipated Events: events not reported as potential risks (section XI.A.) 
a. Unanticipated serious adverse events are defined as any serious adverse event 
related to the health or safety or any life-threatening problem or death caused by, 
or associated with, a device, if that event, problem, or death that was not 
previously defined in nature, severity, or degree of incidence in the literature or 
investigational plan. It can also include any other unanticipated serious problem 
associated with a device that relates to the rights, safety or welfare of subjects. 
 
3. Serious Adverse Event: Serious injury means an injury or illness that: 1) is life-
threatening, 2) results in permanent impairment of a body function or permanent 
damage to a body structure, or 2) necessitates medical or surgical intervention to 
preclude permanent impairment to a body function or permanent damage to a body 
structure.  
a. Permanent means an irreversible impairment or damage to a body structure or 
function, excluding trivial impairment or damage.  
b. Revision cochlear implantation will be considered a serious anticipated adverse 
event. 
 
B. Reporting adverse events 
1. All adverse events will be reviewed by the PI during the preparation of the annual 
reports to the FDA and UNC IRB. Combined adverse events will be listed in an excel 
spreadsheet. Frequent adverse events will be discussed with co-investigators. 
 
2. Anticipated events will be reported to the FDA in the annual report 
 

3. Unanticipated events will be reported to the FDA and UNC IRB within 10 days of the 
investigator becoming aware of the event, as required by 21CFR 812.150. 
 
XIV. 
Monitoring 
 
A. Subjects will be monitored on a case-by-case basis for ongoing or unanticipated medical 
complications. Adverse events will be tracked on a case-by-case basis and recorded in 
study binders at the time of occurrence and followed up at resolution. Any adverse event 
will be reported to the UNC IRB. Should there be concern for the safety of subjects 
because of their participation in the study by the investigators or the UNC IRB, the study 
would be halted at least temporarily and a detailed discussion with the investigators and 
UNC IRB would be undertaken to evaluate the viability of the study. 
 
B. Subjects can withdraw from the study at any time and for any reason by notifying the 
Primary Investigator. If the investigator identifies the need to withdraw a subject from the 
study for any reason, this will be discussed in person during a scheduled evaluation. 
Subjects may also be withdrawn if residual hearing changes in the contralateral (better 
hearing ear) to a moderate hearing loss of worse. In either scenario, the subject will 
continue to receive care irrespective of their participation in the study. 
 
C. Investigative Team 
1. The Principal Investigator will review completed Consent Forms and Case Report 
Forms, including determining candidacy. 
2. The Principal Investigator will ensure that study site Standard Operating Procedures 
are followed by the study team. 
3. Responsibilities for all study team members will be recorded in a Study Delegation 
Log. Not all team members will be responsible for all activities. 
4. Communications between the Principal Investigator and study team will be 
maintained in the regulatory binder. 
5. Source data will be maintained with completed Case Report Forms (such as, speech 
perception score sheets) when available. 
 
XV. 
Confidentiality 
 
A. Subjects will be assigned a specific, anonymous subject number that will be associated 
with his or her data. Database entry will be by subject number only. All personal 
identifiers will be kept in a separate, secure data file that will be password protected and 
not associated with the study data. Only investigators will have access to the subject 
numbers. 
 
B. Subject specific binders will be maintained in a locked cabinet in the Carolina Crossing 
research lab. Individual data collection sheets will be coded with the subject number and 
placed in the subject specific binder at each interval. For analysis, the data will not 
included identifiable information. 
 

C. Data will not be shared outside the investigative team except during reporting of 
anonymous results. 
 
D. After the closure of the study, subject data will be retained for seven years. At that time, 
paper data will be shredded and destroyed in a HIPAA compliant manner. Electronic 
data will be destroyed following UNC policy. 
 
E. A description of the clinical trial will be available on http://ClinicalTrials.gov. This web 
site will not include information that can identify research subjects. 
 

XVI. 
References 
 
Arndt S, Aschendorff A, Laszig R, Beck R, Schild C, Kroeger S, Ihorst G, Wesarg T (2011). 
Comparison of pseudo binaural hearing to real binaural hearing rehabilitation after cochlear 
implantation in patients with unilateral deafness and tinnitus. Otol Neurotol, 32(1):39-47. 
 
Bosman AJ, Hol MK, Snik AF, Mylanus EA, Cremers CW (2003). Bone-anchored hearing 
aids in unilateral inner ear deafness. Acta Otolaryngol, 123(2):258-60. 
 
Cox RM & Alexander GC (1995). The abbreviated profile of hearing aid benefit. Ear Hear, 
16(2):176-86. 
 
Firszt JB, Holden LK, Reeder RM, Waltzman SB, Arndt S (2012). Auditory abilities after 
cochlear implantation in adults with unilateral deafness: a pilot study. Otol Neurotol, 
33(8):1339-46. 
 
Gatehouse S & Noble W (2004). The speech, spatial and qualities of hearing scale. Int J 
Audiol, 43(2):85-99. 
 
Grantham, DW, Ashmead, DH, Ricketts, TA, Labadie, RF, and Haynes, DS (2007). Horizontal-plane 
localization of noise and speech signals by postlingually deafened adults fitted with bilateral cochlear 
implants. Ear Hear, 28(4):524-41. 
 
Hansen MR, Gantz BJ, Dunn C (2013). Outcomes after cochlear implantation for patients 
with single-sided deafness, including those with recalcitrant Meniere’s disease. Otol 
Neurotol, 34(9):1681-7. 
 
Hol MK, Kunst SJ, Snik AF, Cremers CW (2010). Pilot study on the effectiveness of the 
conventional CROS, the transcanial CROS and the BAHA trancanial CROS in adults with 
unilateral inner ear deafness. Euro Arch Otorhinolaryngol, 267(6):889-96. 
  
Iwasaki S, Sano H, Nishio S, Takumi Y, Okamoto M, Usami S, Ogawa K (2013). Hearing 
handicap in adults with unilateral deafness and bilateral hearing loss. Otol Neurotol, 
34(4):644-9. 
 
Kunst SJW, Leijendeckers JM, Mylanus EAM, Hol MKS, Snik FM, Cremers WRJ (2007). 
Bone-anchored hearing aid system application for unilateral congenital conductive hearing 
impairment: audiometric results. Otol Neurotol, 29(1):2-7. 
 
Newman CW, Jacobson CP, Spitzer JB (1996). Development of the Tinnitus Handicap 
Inventory. Arch Otolaryngol Head Neck Surg, 122:143-8. 
 
Nopp P, Schleich P, D’Haese P (2004). Sound localization in bilateral users of MED-EL 
COMBI 40/40+ cochlear implants. Ear Hear, 25:205-214. 

 
Pelizzone M, Cosendai G, Tinembart J (1999). Within-patient longitudinal speech reception 
measures with continuous interleaved sampling processors for ineraid implanted subjects. 
Ear Hear, 20(3):228-37. 
 
 
Rothpletz AM, Wightman FL, Kistler DJ (2012). Informational masking and spatial hearing 
in listeners with and without unilateral hearing loss. J Speech Lang Hear Res, 55(2):511-31. 
 
Slattery WH 3rd, Middlebrooks JC (1994). Monaural sound localization: acute versus chronic 
unilateral impairment. Hear Res, 75(1-2):38-46. 
 
Van de Heyning P, Vermiere K, Diebl M, Nopp P, Anderson I, De Ridder D (2008). 
Incapacitating tinnitus in single-sided deafness treated by cochlear implantation. Ann Otol 
Rhinol Laryngol, 117(9):645-52. 
 
Van Hoesel RJM, Tyler RS (2003). Speech perception, localization, and lateralization with 
bilateral cochlear implants. J Acoust Soc Am, 114(3):1565-74. 
 
Vermiere K, Van de Heyning P (2009). Binaural hearing after cochlear implantation in 
subjects with unilateral sensorineural deafness and tinnitus. Audiol Neurootol, 14(3):163-71. 
 
Welsh LW, Welsh JJ, Rosen LF, Dragonette JE (2004). Functional impairments due to 
unilateral deafness. Ann Otol Rhinol Laryngol, 113(12):987-93. 
 
Wie OB, Pripp AH, Tvete O (2010). Unilateral deafness in adults: effects on communication 
and social interaction. Ann Otol Rhinol Laryngol, 119(11):772-81. 
 
 

Appendix A: Procedure Timeline 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
1
3
6
9
12
X
X
X
X
X
X
AC Thresholds
X
X
X*
X
X
X
X
X
X
BC Thresholds
X
X
X**
CNC Words
X
X
X
X
X
X
X
X
X
X
Speech Perception in 
Quiet
X
X
X
X
X
X
Speech Perception in 
Spatially Separated 
Noise
X
X
X
X
X
X
Localization
X
X
X
X
X
X
Aided Thresholds 
(contra masked)
X
X
Speech Perception in 
Quiet
X
X
Speech Perception in 
Spatially Separated 
Noise
X
X
Localization
X
X
Aided Thresholds 
(contra masked)
X
X
X
X
X
Speech Perception 
(contra masked)
X
X
X
X
X
Speech Perception in 
Quiet (contra open)
X
X
X
X
X
Speech Perception in 
Spatially Separated 
Noise (contra open)
X
X
X
X
X
Localization (contra 
open)
X
X
X
X
X
X
X
X
X
X
X
X
X
*Air conduction thresholds assessed in the contralateral ear only.
**Only if fluctuation noted in AC thresholds
Aural Rehabilitation
Intervals
Unaided 
Assessment
Sound Field Measures    
[BC Device]
Subjective Questionnaires
Sound Field 
Measures         
[Unaided AU]
Informed Consent
Medical Assessment
Imaging Studies
Tympanometry
Cochlear Implant Surgery
Sound Field Measures            
[Cochlear Implant On]
Candidacy 
Evaluation
Post-Initial Activation Intervals 
(months)
Initial 
Activation
Initial Follow-
Up
Surgery
Preoperative 
Evaluation