Single-Sided Deafness and Cochlear Implants: Performance on Novel Speech in Noise and Sound Localization Testing

Monday, September 30, 2024

9:30 AM – 9:36 AM EDT

Location: MBCC, 231

Disclosure(s):

Nadine I. Ibrahim, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Obada Abdulrazzak, BA:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Madison V. Epperson, MD:

faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Introduction: Though many studies have outlined the potential benefits of cochlear implantation (CI) for single-sided deafness (SSD), few have examined compensatory head movements for SSD with a CI. The objective of this study is to analyze the impact of SSD and CI on listening behavior by quantifying and comparing head movements and speech-in-noise comprehension in a novel testing paradigm modeled after real-world listening demands.

Methods: Normal hearing (n = 19), SSD (n = 6), and SSD-CI (n = 6) subjects underwent our novel combination task in a dark, semi-anechoic chamber. An orienting stimulus followed by Harvard IEEE sentences were presented in diffuse background noise with varying SNR. Subjects wore head trackers and were asked to move naturally, repeat the target sentence, and indicate its source. Speech comprehension means were compared using a Wilcoxon ranksum test.

Results: SSD subjects demonstrate decreased localization accuracy (MAE and linear best-fit across targets), increased head movement onset delay (ms), and greater total head displacement (degrees) compared to controls. CI use resulted in a small relative improvement. SSD localization improved by 24º with a CI (pooled standard deviation = 48). Head movement timing delays do not change meaningfully; however, in optimal SNRs, SSD-CI subjects exhibit similar head displacement to controls. Speech comprehension for target stimuli across SNR was significantly lower for unaided SSD subjects (34%) relative to normal hearing controls (46%) and SSD-CI subjects (43%), (p < 0.001). No difference was noted between SSD-CI and controls (p = 0.21).

Conclusions: While CI can improve SSD localization accuracy, this may not reflect real-world differences in localization, and head movements with or without a CI do not seem to positively impact localization ability. Notably, CI may improve speech comprehension to the level of normal hearing individuals in an environment mimicking real-world simultaneous speech comprehension and localization demands. These results have important implications for patient counseling and improving device expectations.

Presenting Author(s)

Nadine I. Ibrahim, MD

Resident Physician
University of Michigan
Ann Arbor, MI, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.

Co-Author(s)

Obada Abdulrazzak, BA

Medical Student
University of Michigan
Ypsilanti, MI, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
GJ

Gerilyn Jones, AuD

University of Michigan, United States

Disclosure information not submitted.
Madison V. Epperson, MD

Surgical Resident
University of Michigan
Ann Arbor, MI, United States

Disclosure(s):
faculty for this accredited education activity has no relationship(s) with ineligible companies to disclose.
JG

Jackson Graves, PhD

University of Michigan, United States

Disclosure information not submitted.
CK

Carolyn Kroger, PhD

University of Michigan, United States

Disclosure information not submitted.

Senior Author(s)

Renee M. Banakis Hartl, MD, AuD

Assistant Professor
University of Michigan
Ann Arbor, MI, United States

Disclosure information not submitted.