AUDITORY MASKING AND MPEG-1 AUDIO COMPRESSION

In high-quality digital audio coding, a great deal of attention is foc used on the auditory perception process, as the goal of audio compress ion is to attain perceptually-transparent compression and reproduction . Consequently models for perceptual masking are used extensively in a udio coders, allowing quantisation noise to be allocated in the variou s frequency subbands according to a masking function. In this way, qua ntisation noise can be made almost inaudible at the receiver. In this paper, the psychoacoustic phenomenon of auditory masking is described. This is followed by a review of the MPEG-1 (Moving Pictures Experts G roup) international standard for audio compression, including an outli ne of the psychoacoustic models used.