Abstract:

Subjects were asked to match sinusoidal tone glides, of various durations (30--210 ms) and sweep widths (50--600 Hz) around a center frequency of 1000 Hz, with two connected steady-state tones whose frequencies could be controlled independently. The expectation was that short glides would give rise to single perceptual events without any movement in a particular direction, so that the two matching steady-state tones would not show any frequency direction either; long glides, on the other hand, were expected to be perceived as rising or falling tones and matched accordingly. It was hoped that this would provide a basis for an explanation of diphthongs as unitary percepts. However, no effect of duration was found at all; on average, glides were matched with tones whose frequencies corresponded to those reached by the glides after one-third and two-thirds of their course had been completed, regardless of duration.