Related Experiment Video
Updated: Feb 19, 2026
04:32
Sound Source Localization Testing in Single-sided Deafness Following Bone Conduction Intervention
Published on: December 20, 2024
923
Intracochlear Measurements of Interaural Time and Level Differences Conveyed by Bilateral Bone Conduction Systems
Nyssa F Farrell1, Renee M Banakis Hartl, Victor Benichoux
1*Department of Otolaryngology †Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, Colorado.
Summary
Bilateral bone-anchored hearing devices (BAHD) can create binaural cues by modulating intracochlear pressures and stapes velocity. This demonstrates the potential for improved sound localization and speech perception in users of bilateral BAHD.
Area of Science:
- Auditory Neuroscience
- Biomedical Engineering
- Hearing Device Technology
Background:
- Unilateral bone-anchored hearing devices (BAHD) are standard, assuming cross-talk limits binaural cues.
- Bilateral BAHD show promise for improved spatial hearing, but objective binaural cue data is scarce.
Purpose of the Study:
- To objectively measure intracochlear pressures (PIC) and stapes velocity (Vstap) with bilateral BAHD.
- To determine how interaural time differences (ITD) and interaural level differences (ILD) modulate these cochlear inputs.
Main Methods:
- Cadaveric specimens with implanted titanium abutments were used.
- PIC and Vstap were measured using intracochlear probes and laser Doppler vibrometry.
- Stimulation involved pure tones with varied ITD and ILD under ipsilateral, contralateral, and bilateral conditions.
Main Results:
- Bilateral stimulation created complex interference patterns dependent on ITD and frequency.
- ITD variations significantly altered PIC and Vstap, suggesting "ITD to ILD conversion."
- ILD variations produced monotonic changes in PIC and Vstap, favoring ipsilateral stimulation.
Conclusions:
- Interaural time and level differences conveyed by BAHD systematically modulate cochlear inputs.
- Despite complex cross-talk, binaural disparities from BAHD can enhance sound localization and speech-in-noise perception.
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