Is Metrical Foot a Phonetic Object?

The assumption behind this pilot study is that metrical feet are not ‘groups of syllables’ or ‘interstress intervals’ but rather ‘groups of vowels’ extracted from the phonetic material contained between two stresses. We analysed the duration, pitch, intensity and acoustic energy of all vowels in isolated pronunciations of 72 initially stressed items (mono-, di- and trisyllables). The results reveal that pre-fortis clipping of the stressed vowel and final lengthening are interrelated, which suggests that stressed and unstressed final vowels are able to ‘negotiate’ their durations. Such ‘communication’ between the stressed vowels and the final unstressed ones is possible only if a mediating constituent (the foot) is postulated. Most importantly, we found no significant differences (p < .05) between the total acoustic energy and the total vowel duration in words having a different number of syllables, which supports the assumption of foot-level isochrony in English. It was also observed that the significant increase in vowel duration in stressed CVC monosyllables co-occurs with a significantly greater pitch slope, which we interpret to be a tonally driven implementation of minimal foot binarity requirement.