... bit rate speech coding 2. ananalysis-by-synthesis coding scheme for medium bit rates (6 to 16 kb/s)3. asubband/transform-based coding scheme for higher bit rates.Thesethreecodingschemeshavebeenintegratedintoaso-calledverificationmodelthatdescribestheoperationsbothofencodersanddecoders,andthatisusedtocarryoutsimulationsandoptimizations.2A ... [1].Wehaveseenrapidprogressinbitratecompressiontechniquesforspeechandaudiosignals[2]–[7].Linearprediction,subbandcoding,transformcoding, as wellasvariousformsof vectorquantizationandentropycodingtechniqueshavebeenusedtodesignefficientcodingalgorithmswhichcanachievesubstantially ... ConclusionsLowbitratedigitalaudioisappliedinmanydifferentfields,suchasconsumerelectronics,professionalaudioprocessing,telecommunications,andbroadcasting. Perceptualcodinginthefrequencydomainhas paved the way to high compression rates in audio coding. ISO/MPEG-1/Audio coding with itsthree layers has been widely...