Hardware Implementation of a 128kbps Monophonic Audio Coder

The perceptual transform coding algorithm yields perceptually transparent compression at bit rates as low as 4 bits/sample, or 128kbit/sec for monophonic 32kHz sampled audio signals. This bit rate is interesting because it corresponds to the ISDN 2B rate, and makes possible wideband audio transmission over dial-up ISDN links. This paper describes an implementation of this algorithm using six AT&T DSP32 floating point signal processors. Almost the entire algorithm was coded in C and compiled with the DSP32 C Compiler.