Quote Originally Posted by Wichita View Post
When you catch a white perch (drum fish) clean it and when you do cut down through the middle of the head, right behind their eyes are two flat rocks. They use these to make the so called drum sound! Take them out wash them and let them dry. When they dry look on the flat sides and tell me what you see...hint---it is a number, you tell me what you guys find. They also are known as good luck stones. An old timer showed this to me.
I think you are referring to otiliths, also known as ear bones? I use to cut them out of redfish and sheepshead when I was working for FL fish and wildlife, they would use them to age the fish. Pretty cool things, looks like they could make good jewelry.

http://www.abc.net.au/rn/scienceshow/stories/2007/2119488.htm

A little paragraph talking about other ways biologists use them for fish research.