# Optimizing Bilateral and Single-Sided Deafness Cochlear Implants for Functioning in Complex Auditory Environments

> **NIH NIH R01** · UNIV OF MARYLAND, COLLEGE PARK · 2020 · $372,307

## Abstract

ABSTRACT: The vast majority of the roughly 100,000 cochlear-implant (CI) users have severe-to-profound hear-
ing loss, but only receive a single CI in one ear. Yet, not having access to sound in two ears severely hampers
the auditory systems' ability to overcome background noise, which has many consequences including increasing
the amount of effort it takes to communicate. Even with access to sound in both ears, two-ear or “binaural”
benefits for bilateral CI (BI-CI) and single-sided deaf CI (SSD-CI) users are small compared to normal-hearing
listeners. Because of possible frequency mismatch between the two ears, it is unclear if the current standard
approach of programming the CIs maximizes speech understanding for two ears, particularly in environments
with multiple sound sources. Our long-term goal is to understand and maximize speech understanding and bin-
aural benefits imparted by CIs by improving interaural frequency, level, and timing encoding. The next steps
toward this goal and the objectives here are to evaluate interaural frequency mismatch and to develop novel CI
programs (MAPs) to correct for mismatch. Our central hypothesis is that binaural function in BI-CI and SSD-CI
users is suboptimal because of interaural frequency mismatch. Our approach will be to optimize the frequency-
allocation in the poorer ear to minimize the mismatch and potentially improve speech understanding and spatial
hearing. With strong preliminary data in hand, the central hypothesis will be tested by pursuing three specific
aims: (1) Assess interaural frequency mismatch for individual electrodes in BI-CI and SSD-CI users. (2) Compare
the acute functional benefits and limitations for the standard MAP and novel MAPs that minimize interaural fre-
quency mismatch in BI-CI and SSD-CI users. (3) In a longitudinal study, evaluate the extent to which standard
MAP and novel MAPs cause changes in pitch processing, binaural processing, and speech understanding in BI-
CI and SSD-CI users. The expected outcome is improved binaural function for BI-CI and SSD-CI users, without
sacrificing speech understanding. This research is significant because it will produce a positive impact in CI
users' quality of life by improving communication in quiet and noisy environments. This proposal is innovative
because it uses knowledge of binaural neural processing to provide a novel, non-invasive, and inexpensive
method to reprogram CIs for bilateral hearing.

## Key facts

- **NIH application ID:** 9812217
- **Project number:** 5R01DC015798-04
- **Recipient organization:** UNIV OF MARYLAND, COLLEGE PARK
- **Principal Investigator:** Joshua Gary Bernstein
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $372,307
- **Award type:** 5
- **Project period:** 2016-12-01 → 2021-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9812217

## Citation

> US National Institutes of Health, RePORTER application 9812217, Optimizing Bilateral and Single-Sided Deafness Cochlear Implants for Functioning in Complex Auditory Environments (5R01DC015798-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9812217. Licensed CC0.

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