Is the Frequency Content of the Calls in North American Treefrogs Limited by Their Larynges?

Table 2

Relationship between pressure differential (PD) across the larynx and sound frequency (FR), laryngeal airflow (AF), or sound pressure (SP) for three species of treefrogs as fit with straight lines.

Species	Frequency (Hz)	Airflow (dm^3/min)	Sound pressure (Pa)
H. versicolor	FR = 337PD − 33153	AF = 1.573PD − 159.467	SP = 0.415PD − 42.202
P. streckeri	FR = 345PD − 33924	AF = 0.889PD − 90.689	SP = 0.226PD − 23.087
A. crepitans	FR = 600PD − 59450	AF = 0.799PD − 81.504	SP = 0.254PD − 26.040