Effects of talker, rate, and amplitude variation on recognition memory forspoken words

This study investigated the encoding of the surface form of spoken words us ing a continuous recognition memory task. The purpose was to compare and co ntrast three sources of stimulus variability-talker, speaking rate, and ove rall amplitude-to determine the extent to which each source of variability is retained in episodic memory. In Experiment 1, listeners judged whether e ach word in a list of spoken words was "old" (had occurred previously in th e list) or "new." Listeners were more accurate at recognizing a word as old if it was repeated by the same talker and at the same speaking rate; howev er there was no recognition advantage for words repeated at the same overal l amplitude. In Experiment 2, listeners were first asked to judge whether e ach word was old or new, as before, and then they had to explicitly judge w hether it was repeated by the same talker, at the same rate, or at the same amplitude. On the first task, listeners again showed an advantage in recog nition memory for words repeated by the same talker and at same speaking ra te, but no advantage occurred for the amplitude condition. However, in all three conditions, listeners were able to explicitly detect whether an old w ord was repeated by the same talker, at the same rate, or at the same ampli tude. These data suggest that although information about all three properti es of spoken words is encoded and retained in memory, each source of stimul us variation differs in the extent to which it affects episodic memory for spoken words.