Identification and discrimination of sweep tones

Abstract

In Experiment 1, subjects were asked to identify the direction (up or down) of sweep tones centered around frequencies of 400, 1300, and 2700 Hz. Durations were 20, 30, 40, or 50 msec, and the rates of the (unidirectional) sweeps were 0, 5,10, 20, 40, and 60 octaves/sec. The main result was that, on the whole, stimuli with zero- or low-sweep rates were judged to move \lddown,\rd irrespective of the actual direction. Experiment 2 was a discrimination experiment, in which subjects had to discriminate between falling, rising, and level sweep tones centered around 1300 Hz. It turned out that discrimination between rising and falling tones did not differ significantly from discrimination between rising and level tones, indicating again that level tones tend to be perceived as going down. The parameters were chosen in such a way that they resembled those of formant transitions in plosive consonants; some implications with regard to speech perception are discussed. © 1985 Psychonomic Society, Inc.