Optimized velvet-noise decorrelator

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Journal Title
Journal ISSN
Volume Title
Conference article in proceedings
Date
2018-09-04
Major/Subject
Mcode
Degree programme
Language
en
Pages
8
87-94
Series
Proceedings of the International Conference on Digital Audio Effects
Abstract
Decorrelation of audio signals is a critical step for spatial sound reproduction on multichannel configurations. Correlated signals yield a focused phantom source between the reproduction loudspeakers and may produce undesirable comb-filtering artifacts when the signal reaches the listener with small phase differences. Decorrelation techniques reduce such artifacts and extend the spatial auditory image by randomizing the phase of a signal while minimizing the spectral coloration. This paper proposes a method to optimize the decorrelation properties of a sparse noise sequence, called velvet noise, to generate short sparse FIR decorrelation filters. The sparsity allows a highly efficient time-domain convolution. The listening test results demonstrate that the proposed optimization method can yield effective and colorless decorrelation filters. In comparison to a white noise sequence, the filters obtained using the proposed method preserve better the spectrum of a signal and produce good quality broadband decorrelation while using 76% fewer operations for the convolution. Satisfactory results can be achieved with an even lower impulse density which decreases the computational cost by 88%.
Description
Keywords
Acoustics, Audio signal processing, digital filter design
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Citation
Schlecht , S , Alary , B , Välimäki , V & Habets , E A P 2018 , Optimized velvet-noise decorrelator . in Proceedings of the International Conference on Digital Audio Effects . Proceedings of the International Conference on Digital Audio Effects , University of Aveiro , pp. 87-94 , International Conference on Digital Audio Effects , Aveiro , Portugal , 04/09/2018 . < https://ant-s4.unibw-hamburg.de/dafx/paper-archive/2018/papers/DAFx2018_paper_23.pdf >