Clinical trial NCT05494632: Interaural Mismatch in SSD CI Users
Official title: Effects of Interaural Loudness and Pitch Mismatch on SSD-CI Performance
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Outcomes
Lead sponsor: Washington University School of Medicine
Sponsor class: OTHER
Collaborators: name: Cochlear
First posted: 2022-08-10
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: Speech understanding in noise
timeFrame: 6 months
Secondary outcomes:
Other outcomes:
Locations:
city: St. Louis
country: United States
facility: Washington University School of Medicine
state: Missouri
Study officials:
affiliation: Washington University School of Medicine
name: Jill B Firszt, PhD
role: PRINCIPAL_INVESTIGATOR
References: