Interaural Mismatch in SSD CI Users

Not Applicable

Active, not recruiting

• Conditions: Outcomes
• Interventions: Device: Treatment-modifications to CI speech processor program

• Registration Number: NCT05494632
• Lead Sponsor: Washington University School of Medicine

Brief Summary

Interaural loudness and pitch mismatch in single-sided deaf cochlear implant (SSD-CI) recipients reduces binaural processing cues and contributes to performance outcomes, specifically speech understanding in noise and localization. The study aims to improve binaural cues through speech processor program modifications that reduce interaural mismatches.

Detailed Description

Effective binaural processing depends on similar loudness growth functions at each ear. The use of interaural level differences (ILDs), perceived as loudness differences, to locate sound is critical given the inability of cochlear implant (CI) recipients to use interaural time differences (ITDs) in binaural processing. In CI recipients with single-sided deafness (SSD), perceived interaural loudness differences may not be valid indicators of interaural level differences because the CI compresses amplitude. Studies suggest better preservation of ILDs may contribute to improved localization and understanding in noise. Since SSD-CI recipients use only one device, an approach to improve their use of ILDs is to match perceived loudness at each ear.

Binaural processing is also affected when signals of equal frequency are not matched in pitch at each ear. In bilateral CI recipients, the investigators found that the greater the pitch mismatch between ears, the poorer the speech understanding in noise. The investigators want to extend this work to SSD-CI recipients. Through CI program modifications, the study aims to decrease the pitch and loudness mismatch between the CI ear and the normal hearing ear to improve binaural listening abilities, specifically speech understanding in noise and sound localization.

Study Timeline

• Study First Submitted: 2022-08-08
• Study First Submitted QC: 2022-08-08
• Study First Posted: 2022-08-10
• Study Start: 2022-08-12
• Primary Completion: 2024-04-30
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-05
• Last Update Posted: 2024-11-07
• Study Completion: 2025-02-08

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 50

Inclusion Criteria

• Participants for the proposed study will be adults with single-sided deafness. Participants will have at least 6 months experience with their cochlear implant or will be newly implanted with the cochlear implant.

Inclusion criteria for the experienced CI user group and the newly implant group are as follows:

• 18 years of age and older
• Postlingual onset of SSD
• Pure tone average (PTA) at 500, 1000, and 2000 Hz of less than or equal to 30 dB HL in the contralateral ear, known as the normal hearing ear
• Implanted with or chosen to be implanted with a Nucleus cochlear implant
• Full insertion of electrode array

Exclusion Criteria

• • Not meeting the inclusion criteria

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Single arm	Treatment-modifications to CI speech processor program	CI speech processor programming

Primary Outcome Measures

Name	Time	Method
Speech understanding in noise	6 months	Testing in noise will be obtained using the R-Space test which simulates listening in a noisy restaurant. The score is a signal-to-noise ratio that reflects 50% speech understanding in noise.

Trial Locations

Locations (1)

Washington University School of Medicine; 🇺🇸 St. Louis, Missouri, United States