Effects of frequency separation and fundamental frequency on perception of simultaneity of the tones

Abstract

Present study investigated the range of perceptual simultaneity, within which listeners perceive two asynchronous tones as simultaneous, as a function of frequency separation and fundamental frequency of the tones. This function was obtained with frequency separations ranging from 0.03 to 5.00 octaves, and fundamental frequencies ranging from 100 to 800 Hz. Listener’s task was to judge whether the two asynchronous pure tones were perceptually simultaneous or not. Results showed a V-shaped function for the perceptual simultaneity range against the frequency separation regardless of fundamental frequency. The perceptual simultaneity range steeply decreased and then gradually increased with the increment of frequency separation. The breakpoint of the V-shaped function was appeared at around the critical bandwidth. This breakpoint was best predicted by CB (Critical Bandwidth) scale, rather than by ERB (Equivalent Rectangular Bandwidth) or octave scales. These findings supported the notion (Okazaki & Ichikawa,...