Influence of syllable-coda voicing on the acoustic properties of syllable-onset /l/ in English

Properties of syllable onset /l/ that depend on the voicing of the syllable coda were measured for four speakers, representing different non-rhotic British English accents that differ in their phonetic realisation of onset /l/ and in their system of phonological contrast involving onset /l/ and /r/. Onset /l/ was longer before voiced than voiceless codas for all four speakers, and darker for two of them as measured by lower F2 frequency, and for these two and one other as measured by spectral centre of gravity (COG). There were no coda-dependent differences in f0 in the /l/, and F1 frequency differed only for the fourth speaker. The vowel was also longer for all four speakers when the coda was voiced (as expected), while F1 was lower and F2 normally higher. One speaker provided data with fricative or affricate onsets: fricated segments were longer before voiced codas, but no coda-dependent COG differences were found. At least when the onset includes /l/, phonological voicing of the coda seems to be reflected in complex acoustic-phonetic properties distributed across the whole syllable, some properties being localised, others not. We describe these properties as variations in a bright~sombre dimension. In most accents, when the coda is voiceless, the syllable is relatively bright: small proportions of periodic energy which is relatively high-frequency at the syllable edges, and a high proportion of silence or aperiodic energy. When the coda is voiced, the syllable is relatively sombre: a high proportion of periodic energy which is relatively low-frequency at the syllable edges, and relatively small amounts of silence and aperiodic energy. Other accents use other combinations, dependent on the phonetic and phonological properties of liquids in the particular accent. The association of onset darkness and coda voicing does not seem to be ascribable to anticipatory coarticulation of features essential to voicing itself; this observation provides support for nonsegmental models of speech perception in which fine phonetic detail is mapped directly to linguistic structure without reference to phoneme-sized segments. hawkins-nguyen_phon00-21 Hawkins & Nguyen: Syllable-onset /l/ varies with coda voicing 3