Sequential stream segregation affects localisation of diotic tones among tones with time-varying interaural time difference.
In this study, I examined how sequential stream segregation contributes to the detection of diotic tones among tones with time-varying interaural time differences (ITDs). Target (T) and distractor (D) tones, and a silent duration (-) formed a sequence (DTD -) and this sequence was presented repeatedly. A frequency difference was introduced between target and distractor tones. The distractor tones were also given time-varying ITDs to produce a percept of smooth auditory motion along the interaural axis. In half of the trials, the target tones were not given time-varying ITDs, and thus were diotically presented. The task of the listeners was to determine whether the repeated sequences of DTD - had target tones without motion. The sensitivity d' for the detection of diotic target tones was higher with larger frequency differences. On the other hand, the criterion c was lower with larger frequency differences. In another session, I confirmed that proportions of reports "two streams" was positively and negatively correlated with d' and c, respectively. The results indicate that the localisation of a sound image could be influenced by sequential stream segregation in complex sound environments.
Kawabe
Takahiro
T
Kyushu University, 6-19-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. tkawabe@psycho.kyushu-u.ac.jp
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001299:Audiometry; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D006801:Humans; D010897:Pitch Discrimination; D013016:Sound; D013997:Time Factors; D055815:Young Adult