VERY LOW BIT RATE TIME DOMAIN SPEECH ANALYZER FOR VOICE MESSAGING

摘要

A speech analyzer (107) compresses a voice message for transmission and includes an LPC analyzer (406) which derives spectral vectors from segments of speech; a memory (1910) which stores predetermined spectral vectors identified by indexes, the indexes also identifying predetermined voicing vectors stored within a receiver; a quantizer (422) which compares the spectral vector derived with the predetermined spectral vectors to select one of the predetermined spectral vectors; and an output buffer for storing the index identifying the predetermined spectral vector selected. The speech analyzer (107) also includes a pitch determiner (414) which includes a pitch function generator (414) which generates a pitch function from a segment of speech. A pitch enhancer (1116) enhances the pitch function of a current segment of speech utilizing the pitch function of one or more sequential segments of speech and a pitch detector (1118) detects the pitch of the current segment of speech.