On psychoacoustic noise shaping for audio requantization

Author

De Koning, Dreten ; Verhelst, Werner

Author_Institution

Dept. ETRO-DSSP, Vrije Univ., Brussels, Belgium

Volume

5

fYear

2003

fDate

6-10 April 2003

Abstract

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. In this paper, we present a least squares theory for optimal noise shaping of audio signals. It provides a 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

FIR filters; audio signal processing; distortion; least squares approximations; optimisation; quantisation (signal); time-varying systems; audio requantization; audio signals; audio stream word-length; distortions; least squares theory; noise shaping filter coefficients; optimal noise shaping curve; psychoacoustic model; psychoacoustic noise shaping; signal requantization; time-varying signal; Acoustic noise; Audio systems; Feedback; Filtering theory; Filters; Least squares methods; Noise shaping; Nonlinear distortion; Psychoacoustic models; Psychology;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03). 2003 IEEE International Conference on

ISSN

1520-6149

Print_ISBN

0-7803-7663-3

Type

conf

DOI

10.1109/ICASSP.2003.1200004

Filename

1200004