2007
Sound localization under perturbed binaural hearing
Publication
Publication
Journal of Neurophysiology , Volume 97 - Issue 1 p. 715- 726
This paper reports on the acute effects of a monaural plug on directional hearing in the horizontal (azimuth) and vertical (elevation) planes of human listeners. Sound localization behavior was tested with rapid head-orienting responses toward brief high-pass filtered (>3 kHz; HP) and broadband (0.5-20 kHz; BB) noises, with sound levels between 30 and 60 dB, A-weighted (dBA). To deny listeners any consistent azimuth-related head-shadow cues, stimuli were randomly interleaved. A plug immediately degraded azimuth performance, as evidenced by a sound level-dependent shift ("bias") of responses contralateral to the plug, and a level-dependent change in the slope of the stimulus-response relation ("gain"). Although the azimuth bias and gain were highly correlated, they could not be predicted from the plug's acoustic attenuation. Interestingly, listeners performed best for low-intensity stimuli at their normal-hearing side. These data demonstrate that listeners rely on monaural spectral cues for sound-source azimuth localization as soon as the binaural difference cues break down. Also the elevation response components were affected by the plug: elevation gain depended on both stimulus azimuth and on sound level and, as for azimuth, localization was best for low-intensity stimuli at the hearing side. Our results show that the neural computation of elevation incorporates a binaural weighting process that relies on the perceived, rather than the actual, sound-source azimuth. It is our conjecture that sound localization ensues from a weighting of all acoustic cues for both azimuth and elevation, in which the weights may be partially determined, and rapidly updated, by the reliability of the particular cue. Copyright
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doi.org/10.1152/jn.00260.2006, hdl.handle.net/1765/35658 | |
Journal of Neurophysiology | |
Organisation | Erasmus MC: University Medical Center Rotterdam |
van Wanrooij, M., & van Opstal, J. (2007). Sound localization under perturbed binaural hearing. Journal of Neurophysiology, 97(1), 715–726. doi:10.1152/jn.00260.2006 |