Original Paper Amalia Arvaniti Department of Linguistics, UCSD 9500 Gilman Dr. No. 0108 La Jolla, CA 92093-0108 (USA) Tel. +1 858 534 8409, Fax +1 858 534 4789, E-Mail amalia@ling.ucsd.edu Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 2009 S. Karger AG, Basel 0031–8388/09/0662–0046 $26.00/0 Accessible online at: www.karger.com/pho Phonetica 2009;66:46–63 Received: September 15, 2008 DOI: 10.1159/000208930 Accepted: January 8, 2009 Rhythm, Timing and the Timing of Rhythm Amalia Arvaniti University of California, San Diego, Calif., USA Abstract This article reviews the evidence for rhythmic categorization that has emerged on the basis of rhythm metrics, and argues that the metrics are unreliable predic- tors of rhythm which provide no more than a crude measure of timing. It is further argued that timing is distinct from rhythm and that equating them has led to circu- larity and a psychologically questionable conceptualization of rhythm in speech. It is thus proposed that research on rhythm be based on the same principles for all languages, something that does not apply to the widely accepted division of languages into stress- and syllable-timed. The hypothesis is advanced that these universal principles are grouping and prominence and evidence to support it is provided. Copyright © 2009 S. Karger AG, Basel 1. Introduction The existence of two rhythmic categories, stress- and syllable-timing, has been the foundation of phonetic research on rhythm [among many, Bolinger, 1965; Abercrombie, 1967; Lehiste, 1977; Nakatani et al., 1981; Bertinetto, 1989] and has also been occa- sionally employed in phonological research [e.g., Nespor and Vogel, 1989; Coetzee and Wissing, 2007]. However, empirical studies failed for a long time to show evidence for isochrony, the equal duration of feet and syllables in stress- and syllable-timed lan- guages, respectively, that is the cornerstone of the stress-/syllable-timing division. As a result, the notion of rhythmic types began to lose its appeal, despite some evidence that infants can differentiate languages depending on rhythmic type [e.g., Nazzi et al., 1998, 2000; Nazzi and Ramus, 2003] and that speech processing by adults relies on syllables or feet depending on the rhythmic type of the listeners’ native language [Cutler et al., 1986, 1992]. (The use of the mora in the processing of languages classified as mora- timed, such as Japanese and Telugu, has been demonstrated by Otake et al. [1993], Cutler and Otake [1994] and Murty et al. [2007].) The stress-/syllable-timing distinction received renewed interest with the advent of rhythm metrics, formulas that seek to quantify consonantal and vocalic variability and use this quantification to classify languages rhythmically. The first such attempt was made by Ramus et al. [1999]; since then several alternative metrics have been