ECE-700 Filterbank Notes
Phil Schniter · 2008
The figure below illustrates the use of sub-band processing in MPEG audio coding. There a psychoacoustic model is used to decide how much quantization error can be tolerated in each sub-band while remaining below the hearing threshold of a human listener. In the sub-bands that can tolerate more error, less bits are used for coding. The quantized subband signals can then be decoded and recombined to reconstruct (an approximate version of) the input signal. Such processing allows, on average, a 12-to-1 reduction in bit rate while still maintaining “CD quality” audio. The psychoacoustic model takes into account