An EMMA and EPG study on token-to-token variability

The potential role of physical correlates of articulatory variability in vowel production was studied by means of EMMA and EPG. In accordance with Perkell & Nelson (1985), the hypothesis to be tested is that the amount and shape of token-totoken variability is influenced by the amount of palatal contact in such a way that high vowels exhibit different variability patterns than the other vowels. 14 German vowels of three speakers of German were recorded with and without bite-block and in bilabial and velar consonantal contexts repeated 10 times. Statistical results indicated that the amount of tongue variability, measured as the size of the dispersion ellipses describing tongue sensor positions, was constrained by the amount of palatal contact: variability was less when the amount of contacts was large. However, the three subjects exhibited different patterns of variability and only one of them showed a main orientation of the dispersion ellipses that was clearly different for high vowels in a sense that is compatible with data collected on speakers of American English by Perkell & Nelson. These results are discussed with regards to differences in the density of each language specific vowel inventory and the inter-individual variation among German subjects is furthermore attributed, at least partly, to morphological differences in the palatal shape and compensatory strategies.