Optimizing Bilateral and Single-sided-deafness Cochlear Implants for Functioning in Complex Auditory Environments

Official title

Optimizing Bilateral and Single-sided-deafness Cochlear Implants for Functioning in Complex Auditory Environments - Part 2

Overview

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.

Interventions

• Diagnostic test Diagnostic tests of cochlear implant or acoustic hearing function
  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.
• Behavioral Targeted aural rehabilitation of the poorer performing ear
  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.

Primary outcome measures

• Perceptual responses to sound level [Time frame: 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 [Time frame: 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 [Time frame: 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) [Time frame: 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) [Time frame: 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 outcome measures (3)

• Sound Localization [Time frame: 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 [Time frame: 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 [Time frame: Post-treatment - after at least 6 months use of a cochlear implant if CI user. After enrollment for non-implanted listeners with acoustic hearing.]

Eligibility criteria

For Bilateral Cochlear Implant Users Arm:

Inclusion criteria

• 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

Exclusion criteria

• 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:

Inclusion criteria

• 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

Exclusion criteria

• 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 the implanted ear will be excluded
• people with an acoustic pure-tone average threshold (octave frequencies 250-4000 Hz) > 30 dB HL in the non-implanted ear

For Non-Implanted Listeners with Acoustic Hearing Arm:

Inclusion criteria

• audiometrically normal hearing or near-normal hearing, or mild/moderate hearing loss
• Sufficient corrected or uncorrected visual acuity (20/50 or better) to read large-font text

Exclusion criteria

• severe hearing loss
• other known disability or neurological disorder

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Basic science

Study locations

United States · 2 centers

• Walter Reed National Military Medical Center — Bethesda
• University of Maryland, College Park — College Park

Identifiers

NCT: NCT06305039 · 2089705 · 1R01DC020506-01A1

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗