Wavelet Analysis Of Bat Echolocation Signals

The study of the echolocation calls of bat is hotspot and emphases in the world. The speciality of the ecological niche and the calls of bat make it very important to study the echolocation calls of bats. Presently the way of study the echolocation calls of bat is localizated in traditional Fourier analysis. Wavelet analysis because of its good retractility has become an advantaged tool in signal analysis field. We provide a new valid way for studying the echolocation calls of bat by using this tool.This paper applies discret wavelet transform (DWT) to the analysis of echolocation calls of several bats. Taking advantage of retractility and time-delay characteristics of wavelet, this paper solves the problems of fixed resolving power and large redundance of the information caused by traditional sonogram analysis by choosing the scale of wavelet correctly. The computations of the signals were made on a computer in a MATLAB environment. The results of DWT can describe the character of the signal more concisely and more precisely than traditional Fourier analysis. We can find some new character of the echolocation calls of bat, and it is very important for search for new character of bats in animal ecology . DWT is testified to be a new effective way in analyzing the echolocation signals of bats.