The effect of discrimination training on speech perception: Noncategorical perception

Three subjects were given extensive practice in discriminating syllables which differed in voice onset time. For these subjects, there were two major findings. First, discrimination of speech follows normal psychophysical laws: long-onset-time stimuli require larger differences than shorter ones for comparable discrimination. Second, the shape of the discrimination function for experienced subjects is more like a leaning W than an inverted V, the usual shape for naive subjects. The data support a model of speech perception with both an acoustic and a phonetic component. The phonetic component is best characterized as a prototype matching process, with the prototype including information on the simultaneity of formant onset.