Optimizing Bilateral and Single-sided-deafness Cochlear Implants for Functioning in Complex Auditory Environments
2 other identifiers
interventional
300
1 country
2
Brief Summary
Cochlear implants (CIs) are devices that partially restore hearing for people with severe to profound hearing loss. This research focuses on CI users who use bilaterally implanted devices (two CIs, one on each side) and also "single-sided deafness" (SSD) CI users who use one CI together with good acoustic hearing in their opposite ear. The goal is to measure and understand the impact of large input asymmetries across the two ears. These asymmetries are common in BI-CI listeners and always present in SSD-CI users. Although most CI listeners benefit from a second source of auditory input, this project measures how these asymmetries limit speech understanding and spatial hearing. The long-term goal is countering or compensating for input asymmetries. Electrophysiological measures are used to describe the health of the auditory system. Behavioral measures are used to assess if training improves performance. CT imaging is utilized to describe the placement of the CIs.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Dec 2023
Longer than P75 for not_applicable
2 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
December 19, 2023
CompletedFirst Submitted
Initial submission to the registry
February 16, 2024
CompletedFirst Posted
Study publicly available on registry
March 12, 2024
CompletedPrimary Completion
Last participant's last visit for primary outcome
May 31, 2028
ExpectedStudy Completion
Last participant's last visit for all outcomes
May 31, 2028
March 28, 2025
March 1, 2025
4.5 years
February 16, 2024
March 24, 2025
Conditions
Outcome Measures
Primary Outcomes (5)
Perceptual responses to sound level
Interaural loudness mismatch is defined as the difference between the levels required to balance interaural loudness for sequential stimulation and the levels required to perceptually center a sound image in space for simultaneous stimulation. Participants will respond through pressing virtual buttons on a computer screen. Depending on the condition tested, the sounds will be delivered to one or both ears.
Post-treatment - after at least 6 months use of a cochlear implant if CI user. After enrollment for non-implanted listeners with acoustic hearing.
Speech understanding in the presence of masking sounds
Speech understanding will be assessed as the percentage of correctly identified keywords. Subjects will respond through oral report (where the responses will be scored by the experimenter) or through pressing virtual buttons on a computer screen. The speech sounds will be delivered to one or both ears in the presence of different types of masking sounds. In some cases, signal processing techniques will be used to distort the speech signals to simulate asymmetric hearing abilities.
Post-treatment - after at least 6 months use of a cochlear implant if CI user. After enrollment for non-implanted listeners with acoustic hearing.
Computed-tomography scan
A computed tomography temporal bone scan will be used to image the cochlear structures and cochlear implant electrode array located within. This scan will use a standard clinical scanner, with software updated to extend the Hounsfield range to reduce artifact from the metal contacts of the electrode array. This procedure uses radiographic processes, and therefore presents the subject with a safe but nonzero amount of radiation. The CT scan will be analyzed to provide measurements of each array's insertion depth within the cochlea (in degrees and mm), the distance to the cochlear modiolus (mm), and cochlear scalar location.
For CI users: CT scan will be collected from existing medical records with permission or taken after study enrollment. Measurements taken after study enrollment. Not collected for non-implanted listeners with acoustic hearing.
Electrode impedance (transelectrode impedance matrix)
This standard clinical measurement will apply a current to one electrode, and measure the resulting induced voltage at each of the other electrodes in the array, one at a time. This process uses low-level electrical stimulation only intended to measure the impedance of the intervening tissues and fluids of the cochlea, and is rarely even perceived by the subject.
Post-treatment - after at least 6 months use of a cochlear implant if CI user. Not collected for non-implanted listeners with acoustic hearing.
Electrically evoked compound action potentials (ECAPs)
Electrically evoked compound action potentials (ECAPs) will be measured using clinically-available software to track the growth in auditory nerve response (observed \~0.2-0.8 ms post-stimulus onset) as input level is varied from threshold to the maximal level at which the signal is comfortably loud. The slope of input-output function will be measured ( in microvolts/current unit) for each electrode along the electrode array of each cochlear implant study participant.
Post-treatment - after at least 6 months use of a cochlear implant if CI user. Not collected for non-implanted listeners with acoustic hearing.
Secondary Outcomes (3)
Sound Localization
Post-treatment - after at least 6 months use of a cochlear implant if CI user. After enrollment for non-implanted listeners with acoustic hearing.
Perceptual Fusion
Post-treatment - after at least 6 months use of a cochlear implant if CI user. After enrollment for non-implanted listeners with acoustic hearing.
Spectrotemporal ripple sensitivity
Post-treatment - after at least 6 months use of a cochlear implant if CI user. After enrollment for non-implanted listeners with acoustic hearing.
Study Arms (3)
Bilateral Cochlear Implant Users
EXPERIMENTALUnilateral Cochlear Implant Users with Single-Sided Deafness
EXPERIMENTALNon-Implanted Listeners with Acoustic Hearing
OTHERInterventions
Because the cochlear implant participants in the study will use cochlear implant devices that they have already received as part of their standard-of-care treatment, the medical device itself is not an intervention for the purposes of this study. The intervention here will be to carry out diagnostic tests of cochlear implant or acoustic hearing function. This will include perceptual tests of sound localization, speech understanding in noise, binaural fusion, and loudness comparisons.
Subjects will undergo listening practice on a tablet computer over headphones at home. For the test group, the aural rehabilitation will be targeted at the poorer ear. For the comparison control group, a sham aural rehabilitation will present speech to both ears.
Eligibility Criteria
You may qualify if:
- two cochlear implants
- acquired their hearing loss during adulthood or late childhood (post-lingual onset)
- native English speaker
- primarily use oral language
- at least six months of cochlear implant use
- Sufficient corrected or uncorrected visual acuity (20/50 or better) to read large-font text
You may not qualify if:
- people who do not use oral language will be excluded.
- people with less than six months of device use will be excluded
- other known disability or neurological disorder
- women who are pregnant will be excluded from the CT portion of the study
- people with any unaided audiometric tone-detection threshold better than 60 dB HL at standard audiometric frequencies (250-8000 Hz) in either ear will be excluded
- For Unilateral Cochlear Implant User with Single-Sided Deafness Arm:
- one cochlear implant in one ear and a second ear with some acoustic hearing
- acquired their hearing loss during adulthood or late childhood (post-lingual onset)
- native English speaker
- primarily use oral language
- at least six months of cochlear implant use
- Sufficient corrected or uncorrected visual acuity (20/50 or better) to read large-font text
- people who do not use oral language will be excluded.
- people with less than six months of device use will be excluded
- other known disability or neurological disorder
- +8 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (2)
Walter Reed National Military Medical Center
Bethesda, Maryland, 20889, United States
University of Maryland, College Park
College Park, Maryland, 20742, United States
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Matthew J. Goupell, PhD
University of Maryland, College Park
- PRINCIPAL INVESTIGATOR
Joshua G. Bernstein, PhD
Walter Reed National Military Medical Center; University of Maryland, College Park
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- NON RANDOMIZED
- Masking
- NONE
- Purpose
- BASIC SCIENCE
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Professor, Department of Hearing and Speech Sciences
Study Record Dates
First Submitted
February 16, 2024
First Posted
March 12, 2024
Study Start
December 19, 2023
Primary Completion (Estimated)
May 31, 2028
Study Completion (Estimated)
May 31, 2028
Last Updated
March 28, 2025
Record last verified: 2025-03
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP, ICF
- Time Frame
- Following publication, available for at least seven years.
- Access Criteria
- Investigators whose proposed use of the data has been approved by an independent review committee
De-identified data that document, support, and validate research findings will be made available when the main findings have been accepted for publication. De-identified data relevant to the project will be disseminated to researchers on and off-campus by request and review of the PI. After publication, research products from this project will be archived at the Digital Repository at the University of Maryland(DRUM). DRUM is a long-term, open access repository managed and maintained by the University of Maryland Libraries. Researchers and the general public can download data and code files, associated metadata and documentation, and any guidelines for reuse.