Implicit learning leads to familiarity effects for intonation but not for voice

Previous studies have shown that speech processing is accelerated for familiar voices in contrast to unfamiliar ones (e.g. [1]), and for familiar intonation in contrast to unfamiliar intonation [2]. The present experiments probed these effects in a single experiment and tested whether they also occur with short, implicit familiarization. Results of two auditory lexical decision tasks (Experiment 1 with a task-based familiarization phase and Experiment 2 with a passive listening familiarization phase), showed that familiarity with the intonation (rise vs. fall) affected reaction times but that familiarity with the voice (speaker A vs. B) did not. Our results suggest that intonation (which contributes to utterance interpretation) is stored in the mental lexicon, but voice information is not.