The influence of epilarynx area on vocal fold dynamics.

Objective: This study investigated the influence of epilarynx area on an excised human vocal fold during phonation.
Study Design: A hemilarynx set-up using an excised human larynx was used. An artificial vocal tract with an epilarynx tube of variable cross-sectional area was attached. High-speed imaging was performed and standard phonatory variables were measured.
Results: Glottal airflow, fundamental frequency, and sound level increased as a function of subglottal pressure. A decrease in epilarynx area decreased phonation threshold pressure, glottal airflow, and vocal fold displacements and velocities.
Conclusions: Preliminary experimental results confirm that narrowing the epilarynx area facilitates phonation by decreasing phonation threshold pressure, presumably through impedance matching of the glottal source and vocal tract.
Significance: As this phenomenon associated with epilarynx narrowing is further quantified and generalized, eventually new surgical alterations of the epilaryngeal structure may be suggested to facilitate phonation, in addition to standard phonosurgical procedures.