Vowel Compression in Altiplateau Mexican Spanish

Abstract

This paper presents an exploratory study of coda-driven vowel compression in Altiplateau Mexican Spanish (AMS). Previous research has led to the claim that pan-dialectal, coda-driven compression does not occur in Spanish and that, instead, only onset complexity drives the shortening of following vowels (Aldrich & Simonet 2019). Based on acoustic analysis of continuously read speech, we find that mid and low vowels in AMS centralise in closed unstressed syllables, and they also display significant shortening in CVC contexts (relative to their uncompressed duration in CV syllables). By contrast, onset complexity does not induce significant compression in our data. Inferential testing confirms that it is an interaction between stress and syllable structure (i.e. coda presence in unstressed syllables) that is most significant in driving both qualitative and quantitative compression. We argue that phonologically constrained, coda-driven compression occurs in Spanish, but it is dialect-specific and stress-dependent. We consider the implications of these variety-specific patterns in the context of debates concerning Spanish resyllabification, phonological rhythm and the acoustic marking of stress.