What is the Pickerel Frog's call?

The sound "pt-zeee" is the distinctive call of the Little Grass Frog (Pseudacris ocularis).

Specifically, the Little Grass Frog's call is the highest pitched of all North American frog voices. It is pitched at about 5-6 kHz. The insect-like chirp is made at the rate of about one per second. There is a very brief introductory note that may be missed by the listener and that is followed by the distinct trill mentioned above.

A chorus of Little Grass Frogs sounds like a field of crickets.