http://www.wired.com/wiredscience/2012/02/jurassic-cricket-song/
Basically some scientists were able to extrapolate the sound of a particularily well preserved jurrasic era cricket, by known the approximate mineral composition of the long dead one, the structure, and making use of what we know about close modern ancestors. Were you standing in a forest jungle somewhere on pangea or whatever the supercontinant was called back then, you might very well have heared exactly this sound.
I dunno about you, but this science **** is neat!