Illusory continuity of periodic sounds: A comparisan of tonal and infratonal temporal induction

Abstract

Tones may appear to remain on continuously when alternated with sounds having appropriate spectral composition and intensity. The limiting conditions for this illusory continuity have been used to define the characteristics of neural spectral (place) analysis of tones. The present study extends investigation of the apparent continuity of interrupted complex periodic sounds to infratonal frequencies, exploring the range of repetition frequencies from 10–2000 Hz. Evidence is presented indicating that reconstruction of obliterated segments of periodic sounds need not be based upon the neural place mechanisms associated with perception of tones. It appears that illusory continuity of periodicity can involve a perceptual synthesis based upon neural temporal information, and that explanations for the limits of illusory continuity of tones (“pulsation thresholds”) solely in terms of a frequency domain analysis involving neural place information may be incomplete. [Work supported by AFOSR.]