Speech synthesis method based on application-specific synthesis units and its implementation on a 32-bit microprocessor

This paper presents a new method for text-to-speech synthesis with application-specific synthesis units. Since in text-to-speech systems, synthesis units are generally designed to cover all possible phoneme strings, such units are inefficient for a specific vocabulary. In the proposed method, synthesis units are selected from a speech database in order minimize the expected distortion of a given vocabulary. This method approximately halves the required amount of memory compared with synthetic units based on a conventional method. Moreover, with the proposed method, synthetic units can be generated according to the required memory. The performance of the speech synthesis was evaluated by making a trial system with a 32-bit microprocessor. Experimental results show that synthetic speech of sufficiently high quality can be obtained with only a few hundred kilobytes of memory and about 1.5 MIPS of computational power.