SPEECH SIGNAL QUANTIZATION USING HUMAN AUDITORY MODELS IN PREDICTIVE CODING SYSTEMS

摘要

A speech compression system called "Transform Predictive Coding", or TPC,provides for encoding 7 kHz wideband speech (16 kHz sampling) at a target bit-rate rangeof 16 to 32 kb/s (1 to 2 bits/sample). The system uses short-term and long-termprediction to remove the redundancy in speech. A prediction residual istransformed andcoded in the frequency domain to take advantage of knowledge in human auditoryperception. The TPC coder uses only open-loop quantization and therefore has afairlylow complexity. The speech quality of TPC is essentially transparent at 32kb/s, verygood at 24 kb/s, and acceptable at 16 kb/s.