From interfaces to system embedding: Phonetic contrasts in the lexicon

The analysis of phonetic systems largely operates independently of other linguistic systems. This is despite the fact that the critical components of the system - phones and the contrastive relations between them - are definitionally linked to higher order systems such as the mental lexicon. In this paper we outline an alternative approach where the phonetic system is studied as embedded within these higher order systems. We show that system embedding radically changes the assumed role of different contrasts in the system and warps estimates of the relative weight of the corresponding acoustic dimensions that delineate that system. Specifically, we compare three models of obstruent discrimination in English: (1) the canonical, inventory model, where contrasts are studied between phones in controlled syllables balanced in weight; (2) the lexicon model, where all contrasts are between real words; and (3) an intermediate, weighted inventory model, where the acoustics are derived from controlled syllable data but the items are sampled to match the distribution of contrasts in the lexicon. By comparing these three models we are able to identify discrepancies in the role of each acoustic dimension under different system assumptions and model their impact on phonetic generalizations.