An analysis of velopharyngeal timing in normal adult speakers using a microcomputer based photodetector system.

Using a microcomputer interface and dedicated software, a photodetector was employed to collect data on the timing of velopharnygeal movements during the production of speech by 10 normally speaking adult subjects. The duration of velopharnygeal closing gestures varied consistently across productions of /m/, /n/ and /n/ in both normal and fast speech. Velopharyngeal opening movements also appeared to be affected by the nasal consonant that was produced. These phenomena are explained in terms of biomechanical constraints known to act upon the velopharyngeal mechanism.