Title :
On psychoacoustic noise shaping for audio requantization
Author :
Verhelst, Werner
Abstract :
Summary form only given. Signal requantization to reduce the word-length of an audio stream introduces distortions. Noise shaping can be applied in combination with a psychoacoustic model in order to make requantization distortions minimally audible. The psychoacoustically optimal noise shaping curve depends on the time-varying characteristics of the input signal. Therefore, the noise shaping filter coefficients are to be computed and updated on a regular basis. We present a least squares theory for optimal noise shaping of audio signals. It provides shorter and more straightforward proof of known properties, and in contrast with the standard theory, it does show how noise shaping filters that attain the theoretical optimum can be designed in practice.
Keywords :
acoustic distortion; acoustic noise; audio coding; filtering theory; hearing; least squares approximations; quantisation (signal); random noise; audio requantization; audio stream; filter coefficients; least squares theory; psychoacoustic noise shaping; requantization distortion; signal requantization; time-varying characteristics; word-length reduction; Noise shaping; Psychology;
Conference_Titel :
Applications of Signal Processing to Audio and Acoustics, 2003 IEEE Workshop on.
Print_ISBN :
0-7803-7850-4
DOI :
10.1109/ASPAA.2003.1285808
