Differentiating tongue shapes for alveolar-postalveolar and alveolar-velar contrasts

Publication date: Available online 13 August 2019Source: Speech CommunicationAuthor(s): Natalia ZharkovaAbstractThis paper is focussed on differentiating midsagittal tongue shapes for alveolar-postalveolar and alveolar-velar contrasts in place of articulation. In addition to two established measures assessing the shape of a tongue curve, three new indices are introduced, which capture more fine grained distinctions in tongue shape, through quantifying the extent of curvature at different locations along the tongue contour. In order to establish whether the indices can be applied across a range of ultrasound recording settings, including those where the transducer is hand-held rather than stabilised in relation to the head, the length of the tongue curve was systematically manipulated, since differences in the length of the imaged tongue contour are likely to occur in non-head-stabilised recordings. The study identified the measures that differentiated between contrasting places of articulation, producing robust results regardless of differences in the length of the imaged tongue curve. Combinations of measures were found to capture place of articulation distinctions more accurately than individual measures. The paper includes a discussion of how such combinations of measures can be used for studying the development of phonological contrasts in typical child speech, as well as the realisation of alveolar-postalveolar and alveolar-velar oppositions in disordered speech.
Source: Speech Communication - Category: Speech-Language Pathology Source Type: research