Coarticulation patterns in identical twins: an acoustic case study

This study reports on an investigation into the coarticulation patterns of a set of young adult male monozygotic (identical) twins, based on a speech corpus of monosyllabic words. The monosyllabic words were of the structure CVC, and were chosen to represent a variety of consonantal and vowel contexts. Coarticulation patterns were investigated by deriving F2 locus equations [e.g., 9, 10, 11] and examining patterns of formant frequency changes (excursions) of the first three formant frequencies (F1 to F3 in Hz) by the place of articulation of the initial consonants. Rates of formant frequency change were also examined. Results indicated that there were both similarities and differences in the twins' coarticulation patterns. For example, both twins displayed similar coarticulation patterns across bilabial, alveolar, velar and glottal places of articulation, which was supported by similar F2 locus equation functions for both twins. In contrast, there were some inter-twin differences in formant frequency changes, and rates of formant frequency changes. The details of these results are presented and discussed.