Recovery from selective adaptation to a voiceless VOT stimulus

Recovery from selective adaptation to a voiceless VOT stimulus was determined by having a group of subjects identify stimuli varying in VOT duration as /p/ or /b/ before adaptation, immediately following each of a series of 1 min adaptation trials, and at 1‐, 4‐, and 7‐min intervals following adaptation. Shifts in phonetic boundary loci (in milliseconds) were obtained between preadaptation and adaptation conditions and between adapatation and postadaptation conditions; recovery was measured in percentage of postadaptation shift. Mean recovery was above 50% in the first minute, above 75% at 4 rain, and tended to level off from 4 to 7 min. By 7 min, more than half the subjects achieved at least 75% recovery and more than three‐quarters achieved at least 50% recovery. The prevailing recovery patterns for subjects reflected either considerable recovery in the first minute with more gradual recovery thereafter or gradual recovery over the entire time interval. No correlation was found between the amount of boundary shift and the degree of recovery for any of the recovery intervals. For the three time conditions, mean pre‐adaptation boundary loci differed by about 1 msec and mean adaptation shifts differed by about 2 msec.