Long-Term Hearing Preservation for Cochlear Implant Recipients with Electrode Contacts in the Functional Hearing Region

Sunday, October 12, 2025

10:00 AM - 10:06 AM EDT

Location: 244

Disclosure(s):

Nicholas J. Thompson, MD:

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

Introduction: Recent studies have shown that roughly 60% of cochlear implant (CI) recipients with preserved low-frequency hearing have one or more electrode contacts at or within the functional acoustic hearing region. It is unknown if the presence of electrode contacts in the functional acoustic hearing region influences long-term hearing preservation. The primary aim of the current study was to review the influence of proximity of the electrode array to the functional acoustic hearing region on shifts in low-frequency unaided thresholds at 1-year post-activation and subsequently >3 years post-activation.

Methods: A retrospective review of adult CI recipients of a lateral wall electrode array from 2017-2022 was performed to identify those who had functional acoustic hearing preservation ( < 80 dB HL at 250 Hz) at device activation. Proximity was quantified as the angular insertion depth (AID) of the most apical electrode, based on imaging, relative to the tonotopic region of preserved hearing. Positive values indicate placement within the functional acoustic region; negative values indicate placement basal to the functional acoustic region. The low-frequency pure tone average (LFPTA; 125, 250, 500 Hz) was queried from the preoperative, device activation, and 1- and >3 years post-activation visits. Stepwise regression analyzed whether proximity, AID, age at surgery, biological sex, and preoperative LFPTA were significant predictors for change in unaided hearing thresholds.

Results: 106 CI recipients (57 female) met inclusion criteria. AID ranged from 330 to 717 degrees (mean 513, SD 79) with proximity values ranging from -183 to 442 degrees (mean 35, SD 110). None of the reviewed independent variables, including proximity, significantly predicted the shift in unaided hearing thresholds at the 1-year or the >3 year visits (p>0.05).

Conclusions: For the present sample, deeper insertion depths and electrode array placement within the functional acoustic hearing region did not predispose CI recipients to delayed loss of residual hearing.

Presenting Author(s)

Nicholas J. Thompson, MD

Assistant Professor
University of North Carolina
Chapel Hill, NC, United States

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

Co-Author(s)

KB

Kevin D. Brown, MD, PhD

Vice Chair and Joseph P. Riddle Professor of Otolaryngology Head and Neck Surgery and Neurosurgery
University of North Carolina
Chapel Hill, NC, United States

Disclosure information not submitted.
EB

Emily Buss, PhD

University of North Carolina, United States

Disclosure information not submitted.
EN

Evan P. Nix, MD

University of North Carolina, United States

Disclosure information not submitted.
AO

Andrea B. Overton, AuD

University of North Carolina, United States

Disclosure information not submitted.
AS

A. Morgan Selleck, MD

University of North Carolina, United States

Disclosure information not submitted.
MD

Matthew M. Dedmon, MD, PhD

University of North Carolina, United States

Disclosure information not submitted.

Senior Author(s)

MD

Margaret T. Dillon, AuD, PhD

University of North Carolina, United States

Disclosure information not submitted.