Speech rhythm in Akan/Twi: A preliminary experiment

Abstract

This study explores the rhythmic timing patterns of Akan/Twi, a West African tone language thought to be syllable-timed, using the Speech Cycling Task (Cummins & Port, 1998; Port, 2003, 2007; Tajima & Port, 2003). How rhythm appears in tone languages without stress/accent is poorly understood. In the Speech Cycling Task, speakers were expected to place prominent elements within rhythmic modes, where specific syllables are pronounced more frequently in certain temporal regions. To uncover which syllables are considered rhythmically prominent, a previous tapping experiment (Darwin & Donovan, 1980; Donovan & Darwin, 1979; Purvis, 2009) was used in which subjects displayed entrainment between tapped beats and specific syllables (akin to stress-timing), rather than beat entrainment with all syllables. Prominent elements should also be resistant to temporal displacement when syllables are inserted between them and temporal compensation should occur when syllables can be deleted. The data included 20 phrases ranging from 4 to 8 syllables in length and four tone melodies (H, L, HL, and LH) repeated at varying rates. Results suggest subjects prefer certain rhythmic modes and that displacement and compensation occur such that rhythmic patterns change. Implications for the stress-timing/syllable-timing dichotomy and how tonal melodies affect rhythmic patterns are discussed.