Vocal efficiency in tracheoesophageal phonation

Abstract

Objective Voice rehabilitation after total laryngectomy is challenging. In order to investigate and understand the function of the neoglottis sophisticated measurements need to be made. During voice production, aerodynamic energy is transformed into sound energy. In non-laryngectomized patients, the voice production efficiency is called the vocal efficiency. Vocal efficiency is an indication of how efficient the transformation of energy takes place. Vocal efficiency is calculated by dividing the output sound power by the aerodynamic power. Patients and methods In a group of eight laryngectomees with tracheoesophageal voice, we measured aerodynamic and acoustic quantities and calculated vocal efficiency. We used a computer setup with airflow transducers, pressure transducers, mikrotip transducers and sound intensity measurement to allow calculation of the needed parameters. Results The tables show the results of the power used and produced in various phonatory tasks. Relatively high levels of aerodynamic power are interpreted as increased effort to speak. Conclusion The aerodynamic power is an indication of the effort needed for voice generation. The efficiency of TE-voice production is lower compared to laryngeal voice production but does show an increase when sound intensity increases, a known phenomenon in healthy laryngeal voice production.