Contemporary review: Impact of primary neopharyngoplasty on acoustic characteristics of alaryngeal tracheoesophageal voice.

The physiology of the vibratory mechanism in alaryngeal tracheoesophageal speech depends on several factors. The structure and resulting function of the neoglottis (or neopharynx) varies from patient to patient depending on the individual details of the surgical procedure performed, as well as the patient's anatomy. In general, the vibratory segment is a blending of the pharyngeal constrictor muscles, cricopharyngeus, and upper circular fibers of the esophagus. Limited ability to visualize dynamically these three-dimensional structures during rapid events of voice and speech production impedes complete understanding of the vibratory function of the neopharynx. Acoustic studies have elucidated some general characteristics of the pharyngoesophagus and neoglottic vibratory mechanism in the laryngectomized population. A critical degree of tonicity is necessary for apposition of mucosal surfaces in the production of tracheoesophageal voice. Deficiencies in the vibratory segment can usually be managed with various surgical procedures (neopharyngoplasty), resulting in reduced intraesophageal pressure and corresponding increase in fluent, intelligible, effortless speech. The acoustic measures, when correlated with neopharyngoplasty variables, produce many significant associations. Some of them are paramount and deserve further attention.