Timing perception of sequences with no obvious onset: Isochrony detection in sequences of complex tones connected by formant glides
Minoru Tsuzaki, Satomi Tanaka, Hiroaki Kato · The Journal of the Acoustical Society of America · 2006
To investigate the perceptual cues that detect arrivals of new auditory events, the detectability of deviation applied to an isochronous temporal structure was measured. The stimuli were sequences of complex tones whose formant frequencies alternate between two steady values. Five steady parts were connected by four formant glides. The isochronous structure was introduced exclusively in the intervals between the starting points of the glides or in the intervals between the ending points by adjusting the durations of the glides and the steady parts in a compensatory manner. Since the harmonic components stop and start one after the other during the glides, it is difficult to define the arrival of new events in an entirely physical view. The perceptual difference in detectability between the starting and ending conditions and its dependency on the frequency region could reveal the perceptual cues that are effective in extracting temporal relations of auditory events. The results will be compared with those obtained with sinusoidal stimuli whose frequencies were modulated in a similar way as the formant frequency in this paper, and they will be discussed by reference to a computational model of auditory event detection. [Work supported by JSPS No. 16200016.]