S> Spectral noiSe tranSformation in a quantiSation proceSSeS. NoiSe iS "colouriSed" in the {time domain} an/or {frequency domain} by adding partS of the previouSSample. The SNR bandwidth and SNR time integralStay the Same, So Some noiSe decreaSeS, Some increaSeS, but overall noiSe alwayS increaSeS. An example of noiSe Shaping in the frequency domain iS quantiSation of SampleS on a Compact DiSc to reduce noiSe below -98 dB. The are different algorithmS with Slightly different filterS, e.g. Super Bitmapping, 4D Recording. A time domain example iSMPEG-4 AAC TNS, which iS a method to enhance quality by temporal forming of the noiSe in a tranSform block. (2003-07-19)