Aerodynamic studies of laryngectomees after the Amatsu tracheoesophageal shunt operation.

Ten speakers with tracheoesophageal shunts were subjected to aerodynamic investigation. Measurements were made of tracheal pressure, airflow rate, and intensity and fundamental frequency of voice. Airway resistance, pulmonary power, acoustic power, and efficiency of voice were calculated from the data. It was found that intensity and airflow rate showed a tendency to augment with increased tracheal pressure, while fundamental frequency remained almost unchanged as tracheal pressure increased. Airway resistance of the tracheoesophageal speakers ranged from about 100 to 1,200 dyne s/cm5 and tracheal pressure ranged from 12 to 80 cm of water, while efficiency of voice ranged from 0.3 X 10(-4) to 6.5 X 10(-4). These results revealed that compared to the normal larynx, efficiency of voice was approximately the same, although airway resistance and tracheal pressure were substantially greater.