Asymmetries in tongue-palate contact during speech
Jo Verhoeven, Naomi Rachel Miller, Luc Daems, Constantino Carlos Reyes-Aldasoro (see publication in Journal )Abstract
Research has shown that speech articulation tends to be asymmetrical in the transverse plane of the vocal tract. A recent meta-study of previously published electropalatograms revealed that 83% of these images show asymmetrical tongue-palate contact [1].
The present study investigated articulation asymmetry on the basis of a large number of electropalatograms acquired in a sentence-reading task at the Centre for Speech Technology Research, Edinburgh University (Mocha: Multichannel Articulatory Database). The vast majority (97.5%) of these palatograms showed some degree of left-right asymmetry, with greater contact on the left-hand side being the more common finding. Asymmetry was not strongly determined by voice or place of articulation. However, it was highly dependent on manner, with fricatives and the lateral approximant showing the greatest degree of asymmetry.
Characterisation of articulation asymmetry could improve our understanding of the speech-production process and its relationship with both neural organisation and the anatomy of the organs of speech.