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Figure 3. Time/position records for mandible and hyoid over 10 sec of normal feeding (A) and for a 10-second extract from the same subject reading the entire ‘Grandfather Passage’ (B). The food (A) was chicken salad spread. The movements of each marker (hyoid, lower canine) are plotted over time relative to the upper occlusal plane (see Fig. 2). Jaw and hyoid movements are clearly rhythmic in A, with synchronization between their movements. The movements of the jaw in speaking are much less rhythmic, with low-amplitude oscillations. In contrast, the antero-posterior movements of the hyoid seem to be slow, while its vertical movements are more rapid. The relatively slow vertical movements of the jaw (from most ‘up’ to next most ‘up’) could represent a single ‘cyclicity’ (see text and MacNeilage, 1998). Reproduced from Hiiemae et al.(2002), with permission from Pergamon Press.
