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Convention Paper

Psychoacoustically Optimal Sigma-Delta Modulation

Authors: Dunn, Chris; Sandler, Mark

AES Convention 99 · Paper 4134 · October 1995

Abstract

A psychoacoustically optimal sigma-delta modulator (SDM) possesses a noise floor with a power spectral density that is invariant with input signal characteristics, and is also minimally audible. While idle tones and noise modulation in sigma-delta modulators can be eliminated by using dither or by making the modulator chaotic, the noise floor attributable to an SDM can be made minimally audible by forcing the noise-shaping characteristic to follow the threshold of hearing. Such an action is possible in higher-order SDMs by appropriate control of noise shaping zero locations, and for a given perceived resolution, has the potential benefit of reduced oversampling factor and/or modulator order. In this paper, optimal zero locations and associated reductions in oversampling factor/modulator order are determined for SDM orders ranging from 2 and 5.

Details

Published in
AES Convention 99
AES Convention
99
Paper number
4134
Publication date
October 6, 1995
Session subject
Conversion Technology
Affiliation
King's College, Strand, London, UK (See document for exact affiliation information.)
Type
Convention Paper