Aerodynamic aspects of voicing: Glottal pulse skewing revisited

Theoretical studies of the voice source in speech production are hampered by the lack of empirical measurements of the aerodynamic events around the glottis. This paper describes an attempt to obtain direct measurements of pressure-flow relations just below and above the glottis during normal speech production. To that end high resolution pressure recordings were made at two points in the trachea and in the pharynx. From these recordings accurate estimates of the flow in the trachea and pharynx can be obtained. It is shown how these estimates can be converted into estimates of transglottal flow. It appeared that the estimates of transglottal flow from tracheal flow are not dependent on the vowel produced. The estimates based on pharyngeal flow, on the other hand, depend to a large extent on the vowel. These findings are interpreted in the framework of acoustic models of speech production.