Method and apparatus for coding audio signals based on perceptual model

Abstract From the Canadian patent

Coding of high quality stereophonic audio signals is accomplished in a perceptual filterbank coder which exploits the interchannel redundancies and psychoacoustic. Using perceptual principles switching between a normal and short, window of input samples improve output signal quality for certain input signals,particularly those having a rapid attack. Switching is also accomplished betweencoding of left and right channels and so- called sum and difference channels in response to particular signal conditions. A number of new perceptually based techniques, including improved threshold determinations result in high quality.