Biophysical requirements for new and projected procedures and devices for voice rehabilitation after total laryngectomy.

This paper reviews the state of the art knowledge of laryngeal physiology and evaluates the parameters necessary for voice production following laryngeal surgery for cancer. Data from normal voice production as well as esophageal speech production are used to generate some relationships that must exist in order to produce sound. Included are the relationships between esophageal pressure, subglottal pressure and intraoral pressure, the mechanical constraints of a pseudolarynx, muscle activity during normal and esophageal speech and the role of the tongue, lips, and palate in esophageal speech. Consideration is given to early and current reed-fistula and air bypass surgical procedures. Alternatives to current experimental and commonly used rehabilitation procedures will also be considered. The limiting factors for use of such devices and some requirements for their operation will be considered. Consideration will also be given to the manner in which various kinds of speech can be compared for acceptability and intelligibility.