Precedence-effect thresholds for a population of untrained listeners as a function of stimulus intensity and interclick interval

Abstract

Data are reported from 127 untrained individuals under lag-and single-click conditions in a precedence-effect task. In experiment I, each subject completed ten runs in a two-interval forced-choice design under a lag-click condition and three runs under a single-click condition. The cue to be discriminated was an interaural time difference ͑ITD͒. Stimuli were 125-s rectangular pulses and the interclick interval ͑ICI͒ was 2 ms. Subjects were randomly assigned to three groups of approximately 30. Each group was tested at one stimulus intensity ͑43, 58, or 73 dB͒. Mean threshold within each group was greater than 500 s for lag-click ITD conditions, although substantial intersubject variability and a clear effect of stimulus intensity on lag-click ITD thresholds were observed, with lower thresholds for higher intensities. In experiment II, the ICI was varied from 0.3 to 10 ms, and thresholds were obtained from groups of approximately 20 untrained subjects. Data were also collected from three highly experienced observers as a function of ICI. The best naïve subject produced mean thresholds near, but not as low as those obtained from experienced subjects. Analysis of adaptive-track patterns revealed abrupt irregularities in threshold tracking, consistent with either losing the cue or listening to the wrong cue in an ambiguous stimulus.

Auditory Spatial Perception: Auditory Localization

“…Langford (1994) and Saberi and Antonio (2003; observed some, but small, gender-related differences in the discrimination of ITD and IID cues, with female listeners being somewhat less sensitive and more variable in their performance than male listeners. Larger gender-related functional asymmetries in auditory spatial perception have been reported by Lewald (2004).…”

“…Some authors attribute this ability to specific anatomical differences in the shape and size of the head, pinna, and concha (e.g., Middlebrooks and Green, 1991;Wightman and Kistler, 1989b). Saberi and Antonio (2003) further noticed that poor localizers have a tendency to improve their localization performance with training while good localizers do not. These results seem to suggest that the difference between good and poor localizers is not only physiological but may also result from previous exposure to the variety of spatial environments and from lifestyle.…”

Temporal weighting functions for interaural time and level differences. II. The effect of binaurally synchronous temporal jitter

“…A fundamental assumption of binaural adaptation is that lateralization is dominated by onset ITD and ILD at high modulation rates, while post-onset information contributes little to subjects' perception. Correspondingly, TWFs measured in normal-hearing listeners for ITD and ILD carried by highrate acoustic click trains (e.g., 800 Hz, Brown and Stecker, 2010) or in bilateral CI users for high-rate electrical pulse trains (e.g., 600 Hz, van Hoesel, 2008a) generally show high weights at onset and uniformly low weights for individual post-onset clicks, although these and other recent studies of temporal weighting of ITD and ILD (e.g., Saberi and Antonio, 2003;Saberi et al, 2004;Stecker and Brown, 2010) also suggested reduced onset dominance for ILD relative to ITD-a finding in conflict with the notion of equal binaural adaptation for ITD and ILD . The nature of differences in the time courses of ITD versus ILD sensitivity, including the common finding of significant individual differences in sensitivity across listeners, remains an area of great interest to us and others at present (cf.…”

“…The nature of differences in the time courses of ITD versus ILD sensitivity, including the common finding of significant individual differences in sensitivity across listeners, remains an area of great interest to us and others at present (cf. McFadden et al, 1973;Krumbholz and Nobbe, 2002;Saberi and Antonio, 2003;Saberi et al, 2004;van Hoesel, 2008a,b;Litovsky et al, 2010;Stecker and Brown, 2010;Brown and Stecker, 2010;see Sec. IV B).…”

Relationship between the summing-localization behavior and perceived width of sound image

“…For time lags between this value and the echo threshold, the perceived direction of the fused image depends only on information from the preceding sound source. This specific localization phenomenon is called the 'precedence effect' [8][9][10].…”