# Integration of acoustic and electric hearing within or across ears

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 2021 · $331,500

## Abstract

SUMMARY: Increasing numbers of cochlear implant (CI) patients are able to combine residual acoustic
hearing (AH) with electric hearing (EH) in the same ear (electric-acoustic stimulation, or EAS), across ears
(bimodal), or both (biEAS). The benefits of acoustic-electric hearing (AEH) are variable; some CI users even
experience interference between acoustic and electric stimulation patterns. In the clinic, there is little effort
to optimize CI and/or hearing aid signal processing with regard to combined acoustic and electric hearing,
and it is unclear whether acoustic and electric patterns are combined differently within or across ears. EAS
and biEAS patients may experience energetic interference between the current spread from EH and the
spread of excitation (SOE) from AH. Bimodal, EAS, and biEAS patients may also experience informational
interference because the same acoustic input may be delivered to different cochlear places (tonotopic
mismatch) within and/or across ears. To mitigate these adverse effects, the optimal fitting for CI and/or
hearing aid devices might be quite different for AEH than for EH and/or AH.
 The long-term goals of this proposal are to understand the mechanisms that underlie integration of
acoustic and electric hearing, which can be used to improve AEH benefits for CI users. We hypothesize that
acoustic and electric stimulation patterns are integrated differently within and across ears. Specifically, we
hypothesize that integration for EAS listeners is limited by both energetic and informational interference;
reducing the current spread/SOE between AH and EH and reducing tonotopic mismatch may improve
integration. We also hypothesize that integration for bimodal listeners is limited by informational interference,
due to tonotopic mismatch and sound quality differences across ears; improving the sound quality of EH
(e.g., focused stimulation) while reducing the tonotopic mismatch between AH and EH may improve
integration. Acoustic-electric integration will be evaluated in pairs of parallel experiments with normal-hearing
(NH) subjects listening to simulations of AEH and in real EAS, bimodal, and biEAS CI listeners. Speech
measures (vowel and sentence recognition in quiet and in noise, vocal emotion recognition) and frequency
resolution will be collected with AH, EH, and AEH, and evaluated in terms of overall AEH performance, AEH
benefit (performance difference between AEH and AH or EH), and integration efficiency (the ratio between
observed and predicted AEH performance). Aim 1 will primarily explore aspects of electric hearing that affect
acoustic-electric integration while Aim 2 will focus on aspects of acoustic hearing that affect acoustic-electric
integration. The proposed research is of great theoretical interest, as it will provide greater insight into
acoustic-electric integration for AEH. The proposed research is also of great clinical value, as the results
may provide better guidance for optimizing CI signal proc...

## Key facts

- **NIH application ID:** 10056216
- **Project number:** 5R01DC016883-03
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **Principal Investigator:** Qian-Jie Fu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $331,500
- **Award type:** 5
- **Project period:** 2018-12-01 → 2023-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10056216

## Citation

> US National Institutes of Health, RePORTER application 10056216, Integration of acoustic and electric hearing within or across ears (5R01DC016883-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10056216. Licensed CC0.

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