protocolSection identificationModule nctId: NCT06305039, orgStudyIdInfo id: 2089705, secondaryIdInfos id: 1R01DC020506-01A1, type: NIH, link: https://reporter.nih.gov/quickSearch/1R01DC020506-01A1, briefTitle: Optimizing Bilateral and Single-sided-deafness Cochlear Implants for Functioning in Complex Auditory Environments, statusModule overallStatus: ENROLLING_BY_INVITATION, startDateStruct date: 2023-12-19, primaryCompletionDateStruct date: 2028-05-31, completionDateStruct date: 2028-05-31, studyFirstPostDateStruct date: 2024-03-12, lastUpdatePostDateStruct date: 2024-03-12, sponsorCollaboratorsModule leadSponsor name: University of Maryland, College Park, class: OTHER, collaborators name: National Institute on Deafness and Other Communication Disorders (NIDCD), collaborators name: Walter Reed National Military Medical Center, collaborators name: Vanderbilt University, descriptionModule briefSummary: 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., conditionsModule conditions: Hearing Loss, conditions: Hearing Loss, Sensorineural, conditions: Cochlear Hearing Loss, designModule studyType: INTERVENTIONAL, phases: NA, designInfo allocation: NON_RANDOMIZED, interventionModel: PARALLEL, primaryPurpose: BASIC_SCIENCE, maskingInfo masking: NONE, enrollmentInfo count: 300, type: ESTIMATED, armsInterventionsModule interventions name: Diagnostic tests of cochlear implant or acoustic hearing function, interventions name: Targeted aural rehabilitation of the poorer performing ear, outcomesModule primaryOutcomes measure: Perceptual responses to sound level, primaryOutcomes measure: Speech understanding in the presence of masking sounds, primaryOutcomes measure: Computed-tomography scan, primaryOutcomes measure: Electrode impedance (transelectrode impedance matrix), primaryOutcomes measure: Electrically evoked compound action potentials (ECAPs), secondaryOutcomes measure: Sound Localization, secondaryOutcomes measure: Perceptual Fusion, secondaryOutcomes measure: Spectrotemporal ripple sensitivity, eligibilityModule sex: ALL, minimumAge: 18 Years, maximumAge: 85 Years, stdAges: ADULT, stdAges: OLDER_ADULT, contactsLocationsModule locations facility: Walter Reed National Military Medical Center, city: Bethesda, state: Maryland, zip: 20889, country: United States, geoPoint lat: 38.98067, lon: -77.10026, locations facility: University of Maryland, College Park, city: College Park, state: Maryland, zip: 20742, country: United States, geoPoint lat: 38.98067, lon: -76.93692, hasResults: False