Stress shift and early pitch accent placement in lexical items in American English

Abstract

The perception of early prominence in late-main-stress words like Mississippi has been described in both metrical and intonational terms. Metrical theory views early prominence as the result of rhythmic stress shift under conditions of stress clash in the metrical grid, while intonation theory attributes early prominence to a tendency for speakers to place the first pitch accent of a phrase as early as possible. We describe an integrated theory of structural and rhythmic aspects of pitch accent placement that combines parts of both approaches, and present evidence to support the theory from perceptual and acoustic analyses of a speech corpus produced in the FM radio news style. We find that early accent placement occurs in contexts which would otherwise result in pitch accent clash, and that the initial accent in an intermediate intonational phrase tends to be located early in its word. Double accents are more common on words that carry all the accents in a phrase (as predicted by phrase onset marking), particularly for words with alternating rather than adjacent lexical stress. Acoustic evidence supports the claim that perceived early prominences typically coincide with pitch accents, and replicates previous results showing no increase in duration for these accented syllables.