Optimization of mel-cepstrum for speech recognition

In this paper we propose a method to optimize the performance of mel-cepstrum that is widely used in speech recognition. Typically, mel-cepstrum is obtained by critical band filters. Thus, the characteristics of filters determine mel-cepstrum, resulting in different performance. By changing the characteristics of filters such as shape, center frequency, and bandwidth, we analyze the performance of mel-cepstrum. Then we propose an algorithm to optimize the filters using the simplex method. Experiments with Korean digit words show that the recognition rate can be improved about 3-5%