The voicing effect is among the most studied and robust of phonetic phenomena. Yet there remains a lack of consensus on why vowels preceding voiced obstruents should be longer than vowels preceding voiceless obstruents. In this paper we provide an analysis of the voicing effect in a corpus of natural speech, and using production data from a metronome-timed word repetition study. From this evidence, as well as the existing literature, we conclude that vowel duration differences follow from consonant duration differences. The characteristic voicing effect in English is largely limited to words of especially long duration, and preceding vowel duration does not reliably cue obstruent voicing under the following circumstances: when obstruent voicing or duration cues conflict; for lax or unstressed vowels; and for most conversational speech. We show that this behavior can be modeled using a competing-constraints framework, where all segments resist expanding or compressing past a preferred duration. Inherent segment elasticity determines the degree of resistance, but segment duration is ultimately determined by the interaction of these segmental constraints with constraints on the distribution of the lengthening force within the syllable, and how closely target durations are matched. This account of the voicing effect has a number of implications for phonological theory, especially the central role that the concept of prominence plays in the analysis of underlying features.
Keywords: Articulatory Phonology; Voicing effect; enhancement; final lengthening; temporal compensation; vowel lengthening.