Plucks and bows are categorically perceived,sometimes

Cutting and Rosner (Perception & Psychophysics, 1974,16, 564–570) reported that sawtooth wavetrains were perceived categorically when an array was varied in linear rise time increments. That is, rapid rise time stimuli were identified as plucked strings and slower rise time stimuli as bowed strings, and pluck-bow comparisons were relatively easy to discriminate but pluck-pluck and bow-bow comparisons were not. Such results indicate the general equivalence of identification and discrimination tasks. Rosen and Howell (Perception & Psychophysics, 1981,30, 156–168), however, report that categorical perception does not occur for these sounds for two reasons. First, the original stimuli did not have the rise times reported by Cutting and Rosner. Second, the perception of these stimuli more closely follows a prediction from a Weber fraction. Acknowledging the first fact to be true, in part due to difficulties in digital-to-analog conversion, I set out to replicate and extend the results of Rosen and Howell. In Experiment 1, I found that stimuli with equal linear increments of rise time are not perceived categorically; but they are not perceived to follow closely a logarithmic relation either. In Experiment 2, I found that stimuli with equal logarithmic increments of rise time were generally perceived categorically. Experiment 3 replicated the results of both experiments. Thus, plucked and bowed music-like sounds can sometimes be found to be perceived in a categorical manner. However, categorical perception is not found with stimuli generated in the manner of Cutting and Rosner (1974) or Rosen and Howell (1981), and the phenomenon generally seems subject to rather stringent, if not curious, stimulus conditions. Moreover, and more deeply, categorical perception seems hardly the bedrock phenomenon it once appeared to be, whether in speech or in any other domain.