Frog activity is an important monitor of lake health.   Again for this season the Brandy Lake frog chatter at night is unbelievable.   You will find a few sites around that offer frog sounds so one can identify the species.    For me it seems there are too many to single out.

Frogs and toads live “on the edge” between water and land. They have semi-permeable skin through which they both breathe and drink.
This makes them very sensitive to pollution and other environmental changes and their numbers are a very good indicator of the health of the lake and its surrounding wetlands.
In the same way that canaries were used in coal mines to signal when dangerous gases were present, the absence, or loss of, frog populations can indicate a disturbed environment…………Read More on this article HERE 

Funny..years ago we had a group of young (city kids) lacrosse players here…sleeping in tents..one kid came in at say 9:30 PM and said in desperation “what’s that noise”? It is frogs..if you could have seen the look on his young face trying to visualise how big they must be to make that kind of noise..well he never went back outside at night.