The Effect of Anatomic Factors on Tongue Position Variability During Consonants

Abstract

Purpose This study sought to investigate the effect of palate morphology and anthropometric measures of the head on positional variability of the tongue during consonants. Method An electromagnetic tracking system was used to record tongue movements of 21 adults. Each talker produced a series of symmetrical VCV syllables containing one of the consonants /t, d, s, z, ʃ, tʃ, k, g, j/ and corner vowels /i, a, u/. Distributions of x , y , and z coordinates at maximum tongue elevation were used to represent tongue position variability across contexts. Anthropometric palate and head measures were also obtained. Results Positional variability of the tongue differed between the front (e.g., alveolar and post-alveolar) and back (velar) consonant groups. A correlational analysis showed that tongue position variability of the front consonants was explained, to a degree, by palate curvature and palate length. The variability of the back consonants was not explained by any structural measures. Conclusion Palate morphology needs to be taken into account when making observations regarding the extent of tongue position variability during consonants in research and in achieving clinical goals.