Interaural Frequency and Loudness Mismatch in SSD CI Users

The Washington University

Status: Completed

Conditions: Outcomes

Treatments: Device: Treatment-modifications to CI speech processor program. Specifically reducing interaural frequency mismatch in experienced SSD-CI recipients.; Device: Treatment-modifications to CI speech processor program to reduced interaural frequency mismatch in newly implanted SSD-CI recipients.; Device: Treatment-modifications to CI speech processor program to reduced interaural loudness mismatch in experienced SSD-CI recipients.

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT05494632

202206085

Details and patient eligibility

About

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.

Full 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.

Enrollment: 45 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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45 participants in 3 patient groups

Period 1: Study 1

Experimental group

Description:

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.

Treatment:

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

Period 2: Study 2

Experimental group

Description:

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.

Treatment:

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

Period 3: study 3

Experimental group

Description:

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.

Treatment:

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