What are the main research contents of speech signal processing at present, and what are their respective goals?

Three aspects of speech signal processing and their respective goals;

1. Speech synthesis.

The purpose of speech synthesis is to let the computer produce high-quality, natural and continuous speech. Computer speech synthesis system, also known as text-to-speech system (TTS), mainly outputs text to speech. Development process: * * peak synthesis, LPC synthesis, PSOLA technology.

2. Speech coding.

In the process of voice signal transmission, the rational use of frequency resources is very valuable, so before transmission, the voice signal should be encoded and compressed.

3. Speech recognition.

Speech recognition involves linguistics, computer science, signal processing, physiology and other related disciplines, and is a branch of pattern recognition. Its main purpose is to make the computer translate speech into executable commands or texts through recognition and understanding.

Main research directions: according to the speech mode, it is divided into isolated speech recognition system, conjunction speech recognition system and continuous speech recognition system. According to the speaker, the characteristic person identification system and the non-characteristic person identification system. According to vocabulary, small vocabulary speech recognition system, medium vocabulary speech recognition system, large vocabulary speech recognition system, unlimited vocabulary recognition system.