Method of transmitting or storing masked sub-band coded audio signals

摘要

PCT No. PCT/EP87/00723 Sec. 371 Date Jul. 21, 1988 Sec. 102(e) Date Jul. 21, 1988 PCT Filed Nov. 20, 1987 PCT Pub. No. WO88/04117 PCT Pub. Date Jun. 2, 1988.In the transmission of audio signals, the audio signal is digitally represented by use of quadrature mirror filtering in the form a plurality of spectral sub-band signals. The quantizing of the sample values in the sub-bands, e.g. 24 sub-bands, is controlled to the extent that the quantizing noise levels of the individual sub-band signals are at approximately the same level difference from the masking threshold of the human auditory system resulting from the individual sub-band signals. The differences of the quantizing noise levels of the sub-band signals with respect to the resulting masking threshold are set by the difference between the total information flow required for coding and the total information flow available for coding. The available total information flow is set and may then fluctuate as a function of the signal.