Native speakers of English identified and then discriminated between stimuli which varied in voice onset time (VOT). One group of listeners identified a randomized sequence of stimuli; another group identified an ordered sequence of stimuli, in which stimuli from the VOT continuum were presented in a consecutive order. Half of theSsin each group then received one of two discrimination formats: the ABX discrimination test in which X was identified with A or with B, or 4IAX test of paired similarity in which two pairs of stimuli—one pair always the same and one pair always different—were presented on each trial. Noncategorical perception of the voicing distinction, reflected by an improvement in discrimination within phonetic categories, was obtained for the group of listeners who experienced both the sequential identification procedure and the 4IAX discrimination test. The results are interpreted as providing evidence for separate auditory and phonetic levels of discrimination in speech perception.