Dimensionality Reduction in Lingual Articulation of Vowels: Evidence From Lax Vowels in Northern Anglo-English

There is a long-standing debate on the relevant articulatory dimensions for describing vowel production. In the absence of a theoretical or methodological consensus, different articulatory studies of vowels rely on different measures, which leads to lack of comparability between different sets of results. This paper addresses the problem of how to parametrise the tongue measurements relevant to vowels, obtained from midsagittal articulatory imaging. We focus on the lax vowels subsystem in Northern Anglo-English. A range of measures quantifying tongue position, height, and shape are extracted from an ultrasound dataset representing 40 speakers. These measures are compared, based on how well they capture the lingual contrast between different vowels, how stable they are across different speakers, and how intercorrelated they are. The results suggest that different measures are preferred for different vowels, which supports a multi-dimensional approach in quantifying vowel articulation.