Call

A call is taken to be any sound of animal origin (whether for communication purposes or not) and includes bird songs/calls, animal vocalizations of any kind, the stridulation of insects, the wingbeats of birds and bats and the various sounds produced by aquatic animals. Calls typically have temporal and spectral structure. For example they may consist of a temporal sequence of two or more syllables (with "gaps" in between) or a set of simultaneous harmonics or formants