Ultrasonic output from the excised rat larynx

Abstract

The source of ultrasonic vocalizations (USVs) produced by rats is thought to be within the larynx. The purpose of this investigation was to determine if the rat larynx is capable of producing ultrasounds with the full range of frequencies reported in vivo. Acoustic output of excised rat larynges with and without vocal fold constriction was measured. At biologically-reasonable airflow rates and pressures, only larynges with a constriction produced the full range of ultrasounds reported in vivo, providing support for the hypothesis that a constriction within the larynx is likely the source of rat USVs.