Pitch-interval analysis of ‘periodic’ and ‘aperiodic’ Question+Answer pairs

International audience; In English Question+Answer (Q+A) pairs, periodicity typically emerges across turn space, to a degree of precision matching standards of music perception. Interactionally-aligned Q+A pairs display such shared periodicity across the turn, while unaligned pairs do not. Periodicity is measured as temporal location of f0 maxima or minima, 'pikes', in successive accented syllables. This study asks whether periodicity of pikes across a turn is accompanied by systematic use of musical pitch intervals across the turn space. Recordings of 77 Q+A pairs from 8 pairs of native English speakers talking naturally. Ratios of f0 in the last pike of the Question and the first of the Answer fell more reliably into Western musical interval categories when the Q+A pair's turn transition was periodic (the Answer was aligned or preferred, re the Question) than when it was aperiodic (disaligned, dispreferred). Similar results were found for ratios of modal f0. Such pitch ratios are better described by musical interval categories of Western tuning systems than by those of three non-Western systems, and best of all by semitones, suggesting close connections between culturally-specific uses of pitch in conversation and in music. Judgments of arousal/valence suggest weak relations with specific pitch intervals. Theoretical implications are discussed.