Artificial Neural Networks As A Classification Method In Mice Calls

This thesis is supported by National Science Fund (No. 10244047). Call is a main behavior of animals. Calls of animals contain important and abundant biological meanings, among which animal characteristics revealing is the most important. Calls based animal classification has become the hotspot of animal taxonomy.Calls based classification is used in avian and insects only recently and still not in mammals in China. Common methods classify animals by their difference in sound pulse rate, wave form structure in time domain and main peak frequency in frequency domain et cetera. Common methods classify mice first by appearance, then by dissection, which need manual operation of professionals and are sophisticated. As an emerging subject, artificial neural network (ANN) has been seen vast development ever since start, and been widely used in the fields of pattern recognition, optimization, image process, signal process, prediction etc, and provided novel and effective method for resolving relevant problem in these fields. Artificial neural network has been widly used in call based classification of individual from the same group and different group from the same species. Little has been done in this field in our country. In this paper ANN is used for classification of mice of different species by the analysis of mice calls. It makes mice classification simple, automatic, exact and fast.In this paper, Summarization of the status of call research and biological meaning of sound communication comes first, with disscussion of classification based on call-pattern recognition and inspection, prevention and cure of pests, mice using their calls. Followed by the introduction of ANN, its basic theory, basic algorithm, merit and defect of back propagation network and ANN application in pattern recognition field. Call based mice classification comes last.Compared with traditional sound recording, we put forward a method for gathering call signals using professional microphone, professional sound card and acomputer. It reduces the processes needed in singal gathering as far as possible and without manual operation. It also makes full use of the automatic program execution ability of computer. So it can automatically record call signals and save gathered data in waveform format to hardisk without stop.Recorded data are processed by program developed in Matlab6.5 using theories of digital signal process, neural network, et cetera. It includes manual analyzation of signal, automatic sound finding and cutting out, automatic feature extraction, neural network training and validation. Experiments are carried on the recorded data of call of five species of mice. For both each species and for both training and validation 45 calls are used. The trained network obtains 100% recognition and more than 90% validation success. The result shows that ANN as a recognition method in calls of mice is very promising, effective and viable.