Interpreting tone of voice: musical pitch relationships convey agreement in dyadic conversation.

Previous research has found that the musical intervals found in speech are associated with various emotions. Intervals can be classified by their level of consonance or dissonance-how pleasant or unpleasant the combined tones sound to the ear. Exploratory investigations have indicated that in an agreeable conversation, the pitches of the last word in an utterance and the first word of a conversation partner's utterance are consonantly related; in a disagreeable conversation, the two pitches are dissonantly related. The present results showed that the intervals between the tonics of the utterances in a conversation corresponded to the agreement between interlocutors.