Interaural Frequency and Loudness Mismatch in SSD CI Users

NCT ID: NCT05494632

Last Updated: 2025-12-26

Study Results

Results available

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Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

45 participants

Study Classification

INTERVENTIONAL

Study Start Date

2022-08-12

Study Completion Date

2025-08-01

Brief Summary

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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

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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.

Conditions

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Outcomes

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Period 1: Study 1

CI speech processor programming in experienced cochlear implant (CI) recipients with single sided deafness. Program changes were made to decrease the interaural frequency mismatch between the CI ear and the contralateral ear.

Group Type EXPERIMENTAL

Treatment-modifications to CI speech processor program. Specifically reducing interaural frequency mismatch in experienced SSD-CI recipients.

Intervention Type DEVICE

We will modify the CI speech processor program to reduce interaural frequency mismatch between the CI ear and the contralateral ear in experienced CI recipients with SSD.

Period 2: Study 2

CI speech processor programming in newly implanted cochlear implant (CI) recipients with single sided deafness. Program changes were made to decrease the interaural frequency mismatch between the CI ear and the contralateral ear.

Group Type EXPERIMENTAL

Treatment-modifications to CI speech processor program to reduced interaural frequency mismatch in newly implanted SSD-CI recipients.

Intervention Type DEVICE

We will modify the CI speech processor program to reduce interaural frequency mismatch between the CI ear and the contralateral ear in newly implanted CI recipients with SSD.

Period 3: study 3

CI speech processor programming in experienced cochlear implant (CI) recipients with single sided deafness. Program changes were made to decrease the interaural loudness mismatch between the CI ear and the contralateral ear.

Group Type EXPERIMENTAL

Treatment-modifications to CI speech processor program to reduced interaural loudness mismatch in experienced SSD-CI recipients.

Intervention Type DEVICE

We will modify the CI speech processor program to reduce interaural loudness mismatch between the CI ear and the contralateral ear in experienced CI recipients with SSD.

Interventions

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Treatment-modifications to CI speech processor program. Specifically reducing interaural frequency mismatch in experienced SSD-CI recipients.

We will modify the CI speech processor program to reduce interaural frequency mismatch between the CI ear and the contralateral ear in experienced CI recipients with SSD.

Intervention Type DEVICE

Treatment-modifications to CI speech processor program to reduced interaural frequency mismatch in newly implanted SSD-CI recipients.

We will modify the CI speech processor program to reduce interaural frequency mismatch between the CI ear and the contralateral ear in newly implanted CI recipients with SSD.

Intervention Type DEVICE

Treatment-modifications to CI speech processor program to reduced interaural loudness mismatch in experienced SSD-CI recipients.

We will modify the CI speech processor program to reduce interaural loudness mismatch between the CI ear and the contralateral ear in experienced CI recipients with SSD.

Intervention Type DEVICE

Eligibility Criteria

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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.


* 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
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Cochlear

INDUSTRY

Sponsor Role collaborator

Washington University School of Medicine

OTHER

Sponsor Role lead

Responsible Party

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Jill B Firszt, PhD

Professor

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Jill B Firszt, PhD

Role: PRINCIPAL_INVESTIGATOR

Washington University School of Medicine

Locations

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Washington University School of Medicine

St Louis, Missouri, United States

Site Status

Countries

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United States

Provided Documents

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Document Type: Study Protocol and Statistical Analysis Plan

View Document

Other Identifiers

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202206085

Identifier Type: -

Identifier Source: org_study_id