Categorical perception of speech without stimulus repetition

We explored the perception of phonetic continua generated with an automated auditory morphing technique in three perceptual experiments. The use of large sets of stimuli allowed an assessment of the impact of single vs. paired presentation without the massed stimulus repetition typical of categorical perception experiments. A third experiment shows that such massed repetition alters the degree of categorical and sub-categorical discrimination possible in speech perception. Implications for accounts of speech perception are discussed.