# Minimizing auditory spatial ambiguities using listener rotation for normal and hearing impaired listeners

> **NIH NIH F32** · ARIZONA STATE UNIVERSITY-TEMPE CAMPUS · 2020 · $66,446

## Abstract

Summary
Listeners integrate multisensory (e.g. vision, vestibular) and multisystems (e.g. motor control, feedback) inputs
with auditory processing to localize sound sources in the world around them. The proposed research aims at an
improved understanding of this process for normal hearing (NH) and hearing impaired (HI) listeners. We will test
moderately impaired listeners who wear hearing aids (HA), and profoundly impaired listeners bilaterally
implanted with cochlear implants (CI), along with NH listeners for baseline measures. NH listeners use head
movements to resolve auditory spatial ambiguities such as front-back confusions, where listeners correctly
estimate the angular position of a sound source but cannot reliably determine if it is in front or behind.
New data collected by Dr. Pastore (paper in press) show that many CI listeners can use rotational head
movements to avoid front-back confusions. Initial pilot data with NH listeners suggest that movement may also
improve localization acuity in reverberation. These preliminary data suggest that HA and CI users may use head
movements to simplify and parse their auditory environment more effectively than lab estimates under stationary
conditions suggest. The knowledge gained from this research should prove valuable to designers of “smart”
processors for cochlear implants and hearing aids.
The Spatial Hearing Laboratory is equipped with a programmable, rotating chair and an azimuthal ring of 24
loudspeakers, synchronized to present stimuli based on listeners' angular velocity and position, offering control
over several dynamic sensory and systems inputs involved in localizing sounds during listener rotation. In this
facility, we will measure two indicators of the benefit of listeners' rotational movement.
The first Aim will continue to investigate CI and HA listeners' ability to resolve front-back confusions in sound
source localization tasks using their own movement by measuring the interaction of stimulus duration and listener
movement in CI listeners' ability to resolve front-back confusions while rotating. This will offer insights into
dynamic auditory spatio-temporal processing in both populations.
The second Aim will investigate NH, CI, and HA listeners' ability to “learn” the acoustic patterns of a modeled
reverberant space and use this to simplify the perceived auditory scene when listeners are rotating versus
stationary. We will measure these listeners' ability to group a single simulated direct sound together with a
simulated reflection into one perceived auditory object located at or near the location of the first presented
stimulus – the so-called “buildup of the precedence effect.”

## Key facts

- **NIH application ID:** 9827481
- **Project number:** 5F32DC017676-02
- **Recipient organization:** ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
- **Principal Investigator:** Michael Torben Pastore
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $66,446
- **Award type:** 5
- **Project period:** 2019-01-01 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9827481

## Citation

> US National Institutes of Health, RePORTER application 9827481, Minimizing auditory spatial ambiguities using listener rotation for normal and hearing impaired listeners (5F32DC017676-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9827481. Licensed CC0.

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