Sound therapy for tinnitus relief for adult cochlear-implant users

INTERVENTION: While Part A of the study seeks to explore objective measures of tinnitus, Part B seeks to assess the effect of sound therapy on tinnitus. In Part B, participants will be asked to come to the research centre for two sessions, each lasting between 2 h 15 min and 2 h 45 min. Breaks will be spaced as needed during the session and tea and refreshments will be provided. If any of the event‐related auditory evoked potentials used in Part A is significantly different across participants with and without tinnitus, the type of evoked potential with the highest sensibility and specificity will be used in Part B. Responses will be obtained at the start of the session. Next, the participant will be presented with a five‐minute duration sound texture or with a control sound, randomly chosen. During the presentation of the sound, participants will be prompted to rate the loudness and annoyance of their tinnitus several times (once per minute) using a computer interface. At the end of the stimulation, the evoked potentials will be repeated. As this is a controlled trial, each participant gets exposed to two sounds, in random order. Therefore, after the first sound was presented, the participant comes back for a second session with the same structure, where the second sound (the sound not presented in the first part of the session) is presented CONDITION: Tinnitus ; Nervous System Diseases ; Tinnitus PRIMARY OUTCOME: ; Part A:; 1. Mismatch negativity: Variables are amplitude, latency, and area under the curve; 2. Auditory Steady State Response and N1‐P2 responses: The variable is amplitude in each case.; 3. P300: The variables are amplitude and latency; For all of these outcome measures (1, 2, and 3), the method of measurement is recording event‐related auditory evoked potentials; 4. Pupillometry: The variable is Pupillar diameter. The method of measurement is pupillometry; ; Part B:; 5. Tinnitus loudness ratings. Methods: Subjective ratings in a visual‐analogue scale; 6. Tinnitus annoyance ratings. Methods: Subjective ratings in a visual‐analogue scale; 7. One objective measure selected based on the outcomes of Part A. It could be 1, 2, 3, or 4. The measure with the highest sensitivity to separate between participants with tinnitus and without tinnitus will be used; SECONDARY OUTCOME: ; Part A:; 1. Variable: Tinnitus Functional Index; Method: validated questionnaire; 2. Variable: Qualitative data describing each participant's tinnitus. Method: Tinnitus Cochlear Implant Questionnaire, non validated questionnaire; 3. Variable: Tinnitus Loudness Ratings; Methods: Subjective ratings in a visual‐analogue scale; INCLUSION CRITERIA: Part A: 1. Adult (aged 18+ years, with no upper limit) 2. Users of unilateral cochlear implants 3. Fluent in English 4. Attend the Emmeline Centre for Auditory Implants 5. Had their cochlear implants switched on for at least one year Part B: 1. Adult (aged 18+ years) 2. Users of unilateral cochlear implants 3. Attend the Emmeline Centre for Auditory Implants 4. Had their cochlear implants switched on for at least one year 5. Have tinnitus even when their cochlear implant is switched on 6. Scored 32 or higher in the Tinnitus Functional Index questionnaire