Contribution of spectral cues to human sound localization.
The contribution of spectral cues to human sound localization was investigated by removing cues in 1/2-, 1- or 2-octave bands in the frequency range above 4 kHz. Localization responses were given by placing an acoustic pointer at the same apparent position as a virtual target. The pointer was generated by filtering a 100-ms harmonic complex with equalized head-related transfer functions (HRTFs). Listeners controlled the pointer via a hand-held stick that rotated about a fixed point. In the baseline condition, the target, a 200-ms noise burst, was filtered with the same HRTFs as the pointer. In other conditions, the spectral information within a certain frequency band was removed by replacing the directional transfer function within this band with the average transfer of this band. Analysis of the data showed that removing cues in 1/2-octave bands did not affect localization, whereas for the 2-octave band correct localization was virtually impossible. The results obtained for the 1-octave bands indicate that up-down cues are located mainly in the 6-12-kHz band, and front-back cues in the 8-16-kHz band. The interindividual spread in response patterns suggests that different listeners use different localization cues. The response patterns in the median plane can be predicted using a model based on spectral comparison of directional transfer functions for target and response directions.
Langendijk
Erno H A
EH
TNO Human Factors Research Institute, Soesterberg, The Netherlands. erno.langendijk@philips.com
Bronkhorst
Adelbert W
AW
D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D013017:Sound Localization / Q000502:physiology*