A study on coarticulatory resistance and aggressiveness for front lingual consonants and vowels using ultrasound

Abstract

A new method for quantifying contextual variability at different regions of the tongue using ultrasound spline data reveals that tongue body coarticulatory resistance for Catalan consonants and vowels in VCV sequences decreases in the progression [ʎ, ɲ, ʃ] > [s, r] > [l, ɾ, t, n] > [ð] and [i, e] > [a] > [o] > [u]. These consonant and vowel hierarchies support the degree of articulatory constraint model of coarticulation according to which coarticulatory resistance depends on whether a given lingual region is involved in the formation of a closure or constriction and on the severity of the manner of articulation requirements. Data show that this coarticulatory scenario holds not only at the palatal zone, as revealed by previous coarticulation studies, but at the velar and pharyngeal zones as well. Partial exceptions are [s] and [i], which may allow for some more contextual variability than expected at the back of the vocal tract. Another major finding is that tongue body coarticulatory resistance and aggressiveness are highly positively correlated. The implications of these experimental results for speech production organization and sound change are discussed.