Objective evaluation of audible aliasing distortion in digital audio synthesis

Abstract

This paper deals with aliasing distortion in digital audio signal synthesis of basic periodic waveforms with infinite Fourier series. There is aliasing when these signals are generated in digital domain because of its unlimited bandwidth. There are several synthesis techniques of these signals designed to avoid or reduce the aliasing distortion but they have high computing demands. Trivial generation of basic periodic waveforms is therefore still effective for sound synthesis when oversampling is used. There will always be the aliasing distortion but some spectral components produced by the aliasing will be masked with harmonic components and thus inaudible. This paper deals with objective evaluation of audible aliasing distortion with the help of a psychoacoustic model of simultaneous masking and compares the computing demands with other methods.