It's not what you say but the way you say it: matching faces and voices

Recent studies have shown that the face and voice of an unfamiliar person can be matched for identity. Here the authors compare the relative effects of changing sentence content (what is said) and sentence manner (how it is said) on matching identity between faces and voices. A change between speaking a sentence as a statement and as a question disrupted matching performance, whereas changing the sentence itself did not. This was the case when the faces and voices were from the same race as participants and speaking a familiar language (English; Experiment 1) or from another race and speaking an unfamiliar language (Japanese; Experiment 2). Altering manner between conversational and clear speech (Experiment 3) or between conversational and casual speech (Experiment 4) was also disruptive. However, artificially slowing (Experiment 5) or speeding (Experiment 6) speech did not affect cross-modal matching performance. The results show that bimodal cues to identity are closely linked to manner but that content (what is said) and absolute tempo are not critical. Instead, prosodic variations in rhythmic structure and/or expressiveness may provide a bimodal, dynamic identity signature.