This paper concerns the extent to which the precedence effect is observed when leading and lagging sounds occupy different spectral regions. Subjects, listening under headphones, were asked to match the intracranial lateral position of an acoustic pointer to that of a test stimulus composed of two binaural noise bursts with asynchronous onsets, parametrically varied frequency content, and different interaural delays. The precedence effect was measured by the degree to which the interaural delay of the matching pointer was independent of the interaural delay of the lagging noise burst in the test stimulus. The results, like those of Blauert and Divenyi [Acustica 66, 267-274 (1988)], show an asymmetric frequency effect in which the lateralization influence of a lagging high-frequency burst is almost completely suppressed by a leading low-frequency burst, whereas a lagging low-frequency burst is weighted equally with a leading high-frequency burst. This asymmetry is shown to be the result of an inherent low-frequency dominance that is seen even with simultaneous bursts. When this dominance is removed (by attenuating the low-frequency burst) the precedence effect operates with roughly equal strength both upward and downward in frequency. Within the scope of the current study (with lateralization achieved through the use of interaural time differences alone, stimuli from only two frequency bands, and only three subjects performing in all experiments), these results suggest that the precedence effect arises from a fairly central processing stage in which information is combined across frequency.
[1]
Tammo Houtgast,et al.
A precedence effect in the perception of inter-aural cross correlation
,
1992,
Hearing Research.
[2]
P L Divenyi,et al.
Binaural suppression of nonechoes.
,
1992,
The Journal of the Acoustical Society of America.
[3]
Brad Rakerd,et al.
Precedence effect with and without interaural differences−Sound localization in three planes
,
1992
.
[4]
P. M. Zurek.
Spectral dominance in sensitivity to interaural delay for broadband stimuli
,
1985
.
[5]
F. Wightman,et al.
The dominant role of low-frequency interaural time differences in sound localization.
,
1992,
The Journal of the Acoustical Society of America.
[6]
P M Zurek,et al.
Adjustment and discrimination measurements of the precedence effect.
,
1993,
The Journal of the Acoustical Society of America.