Plucks and bows are not categorically perceived.

Abstract

Cutting and Rosner (Perception & Psychophysics, 1974, 16, 564–570) reported that nonspeech stimuli differing in rise time were categorically perceived in the same way as speech sounds. With two independently generated sets of stimuli essentially the same as those described by Cutting and Rosner, we were unable to replicate their finding that discrimination measured in an ABX task was best around 40 msec, the category boundary. We found discrimination always best at the shortest rise times, decreasing monotonically with increasing rise time. Oscillographic traces of Cutting and Rosner’s original stimuli showed them not to have the intended rise times. Instead of starting with a rise of 0 msec and increasing linearly in 10-msec steps to 80 msec, the measured rise times were approximately 4, 6, 15, 19, 37, 43, 57, 66, and 76 msec, respectively. A set of stimuli having these rise times was generated. Two distinct patterns of response emerged from the discrimination task. Most subjects now showed best discrimination around 40 msec, but a few still performed best at the shortest rise times.