AUDITORY EVENTS THAT SEEM TO BE FORMED ILLUSORILY FROM OFFSET CUES
It was revealed that a very short tone can be perceived only from an offset cue without any preceding change that can indicate an onset. We presented a harmonic glide tone complex of 2 s that ascended or descended between 200 and 400 Hz. The tone had five glide components, among which one was turned off in the temporal middle. Some listeners could hear a very short illusory tone around the temporal middle embedded in the complex. Subjective properties, i.e., pitch, duration, and loudness, of the tone were estimated employing a method of adjustment, but only with listeners who could hear the illusory tone constantly. Effects of individual listeners were observed systematically, suggesting that the illusory tone was created subjectively depending on each individualâ€™s perceptual framework. The subjective duration of the illusory tone, measured as the point of subjective equality, was always within a range of 40 to 450 ms in four among five participantsâ€”far longer than 20 ms, the lower limit of the adjustment determined as the sum of the rise and the fall time. We suggest that the tone was constructed from a real offset and an illusorily restored onset.