This is a Southern Leopard Frog, and the easiest way to communicate with one is by using a balloon. Inflate the balloon and hold it in one hand. Moisten the fingers of your other hand and rub them firmly against the balloon to produce a sound. You can hear the actual sounds of the Southern Leopard Frog at: http://www.fcps.edu/islandcreekes/ecology/southern_leopard_frog.htm

Think about the sounds a balloon makes as you listen to the frog. Frogs sing to stake out their territory and to attract a mate. If you get near the frogs, they will stop singing, thinking that you are there to eat them. If you imitate their call with a balloon, they will think that other frogs are singing, so it must be safe for them to sing too.