Perception of interaural time differences in electric and acoustic hearing

Authors

  • Bernhard Laback Acoustics Research Institute, Austrian Academy of Sciences, A-1040 Wien, Austria
  • Inge Zimmermann Acoustics Research Institute, Austrian Academy of Sciences, A-1040 Wien, Austria
  • Piotr Majdak Acoustics Research Institute, Austrian Academy of Sciences, A-1040 Wien, Austria

Abstract

Cochlear implant (CI) listeners are sensitive to interaural time differences (ITDs), but their sensitivity is generally lower and more variable across individuals compared to normal hearing (NH) listeners. Previous studies showed sensitivity to ITD in the ne structure, if the pulse rate does not exceed a few hundred pulses per second. Furthermore, introducing binaurally- synchronized jitter was shown to have the potential to overcome this pulse rate limitation. With respect to envelope ITD, basic questions are still open both in normal and electric hearing. In normal hearing, the ITD sensitivity for transposed tones (TTs), a special type of amplitude-modulated high-frequency pure-tones, has been shown to be better than for sinusoidally-amplitude- modulated (SAM) tones. In experiments with nine NH and nine CI listeners we studied which properties of TTs cause the increased ITD sensitivity. We systematically varied the off-time and slope steepness of trapezoidally modulated (27 Hz) carrier signals. The NH listeners showed signi cant effects of off time and slope. The two effects did not interact and the best performance occurred for the longest off time combined with the steepest slope tested. The CI listeners showed only a signi cant effect of the off time. The implications with respect to CI coding strategies are discussed.

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Additional Files

Published

2009-12-15

How to Cite

Laback, B., Zimmermann, I., & Majdak, P. (2009). Perception of interaural time differences in electric and acoustic hearing. Proceedings of the International Symposium on Auditory and Audiological Research, 2, 403–416. Retrieved from https://proceedings.isaar.eu/index.php/isaarproc/article/view/2009-41

Issue

Vol. 2 (2009): Binaural Processing and Spatial Hearing

Section

2009/4. Recent concepts in binaural cochlear-implant and hearing-aid processing

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