Research On Speech Synthesis Algorithm For Low Bit-rate Underwater Speech Communication

With the development of the Speech compression and Wireless broadband network technology, the transmission rate of underwater speech communication has reached a certain standard. For the reason of underwater acoustic channel's own characteristics, it is difficult to transmit in high speed and long distance. The use of speech recognition and speech synthesis technology for source coding and decoding methods, which make it easy to transmit in low bit-rate, can solve the problem of limited acoustic channel capacity. However, in the receiver, the quality of speech synthesis is not ideal. In this paper, a speech synthesis's method is given. The method realizes speech synthesis through speech coding, optimizes synthetic effects through prosodic adjustment, with the characteristics of high synthesis quality and small speech database, especially suited for low rate of embedded underwater speech communication system, and have high engineering practical value.Paper first studied the recommendation G.729A and the regulation laws of prosody parameters between vocabularies, and then simulated the algorithm of recommendation G.729A, made voice database and completed text to speech. On this basis, paper simulated the algorithm of time-period tone pitch, amplitude tone tail, and analyzed prosodic parameter adjustment laws, finally, realized a text-to-speech conversion system of small vocabulary.Through the text-to-speech conversion system's subjective perception test, the results showed that the reconstructed speech was clear and natural, besides, the algorithm had moderate complexity and small delay, which was suitable for underwater micro vector and embedded system of wireless speech communication between divers and submarine.