A speech quality improvement system by means of 1/f fluctuation theory

Up to now there have been no definite method as to how to evaluate human voices or speech qualities generated from an automatic speech system. In this paper, we present a method. to evaluate the voice or speech quality by 1/f fluctuation theory. According to this evaluation method, a promising method to improve speech quality is presented. It is well known that the 1/f fluctuation is an irregular oscillation in the natural physical world and is of comfortable and agreeable sensation for humans. By 1/f fluctuation theory, an original idea to make a speech quality improvement system (SQIS) for improving speech generated from an automatic speech system is developed, therefore a high quality speech can be created by this SQIS. This system has been tested by some simple Japanese utterances. The results show that this method will be a powerful tool for automatic production of high quality speech and for research on automatic prosody generations.