# Binaural Spectral Integration with Hearing Loss and Hearing Devices

> **NIH NIH R01** · OREGON HEALTH & SCIENCE UNIVERSITY · 2022 · $547,367

## Abstract

Project Summary
 Approximately 22 million Americans have a hearing impairment. While hearing devices such as hearing
aids (HAs) and cochlear implants (CIs) are successful in improving speech recognition for many hearing-
impaired individuals, there is still significant variability in benefit, and speech recognition in noise remains a
problem. One factor that may limit benefit, especially binaural benefit, is abnormal binaural spectral integration.
 A prerequisite for binaural integration is binaural fusion — the fusion of stimuli from the two ears into a
single auditory object. Our findings from the previous grant showed that unlike normal-hearing (NH) listeners,
many HA and CI users experience abnormally “broad” binaural fusion in the spectral domain, such that pitches
that differ greatly in frequency between the two ears are still heard as a single percept. Individuals with broad
fusion also experience abnormal binaural spectral integration - averaging and thus distortion of spectral
information across the ears when disparate sounds are fused. We also showed broad fusion to be associated
with binaural interference — poorer speech recognition with two ears compared to one.
 More importantly, preliminary data show that broad fusion is associated with greater difficulty with
understanding speech in challenging multi-talker listening situations, such as noisy restaurants. Difficulties with
speech understanding in noise is a major complaint of both HA and CI users. In order to help hearing-impaired
listeners reduce binaural interference and improve speech understanding in background noise, we need to
understand the underlying causes and factors in broad fusion.
 The long-term goal of this research program is to investigate the effects, causes, and potential treatments
for abnormal binaural spectral integration in hearing-impaired listeners. In this proposal we will: 1) determine
how broad binaural fusion affects speech perception in quiet and in background talkers; and 2) investigate
potential causes of broad binaural fusion in children and adults with HAs and CIs, focusing on peripheral
spectral resolution, auditory experience, and top-down auditory processing factors.
 The proposed research will indicate the role of broad binaural spectral fusion in difficulties faced by
hearing-impaired listeners, especially for speech understanding in background noise. Determination of the
factors underlying broad fusion will inform future rehabilitation approaches to treat broad fusion, and help
hearing-impaired listeners attain the same benefits of binaural hearing as NH listeners.

## Key facts

- **NIH application ID:** 10406925
- **Project number:** 5R01DC013307-09
- **Recipient organization:** OREGON HEALTH & SCIENCE UNIVERSITY
- **Principal Investigator:** Lina A. Reiss
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $547,367
- **Award type:** 5
- **Project period:** 2013-12-01 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10406925

## Citation

> US National Institutes of Health, RePORTER application 10406925, Binaural Spectral Integration with Hearing Loss and Hearing Devices (5R01DC013307-09). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10406925. Licensed CC0.

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