Range effect in the perception of voicing.

The location of the voicing boundary in the perception of initial stop consonants is shown to vary according to the range of voice-onset times used in a block of trials and according to the order in which blocks covering different ranges are presented. Although these range effects introduce methodological complications into the interpretation of adaptation experiments, they appear to be qualitatively different from adaptation effects and, it is suggested, may provide a metric for assessing the auditory tolerance of phonological categories.