The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Thushara D. Abhayapala - One of the best experts on this subject based on the ideXlab platform.
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theory and design of soundfield reproduction using continuous Loudspeaker concept
IEEE Transactions on Audio Speech and Language Processing, 2009Co-Authors: Thushara D. AbhayapalaAbstract:Reproduction of a soundfield is a fundamental problem in acoustic signal processing. A common approach is to use an array of Loudspeakers to reproduce the desired field where the least-squares method is used to calculate the Loudspeaker weights. However, the least-squares method involves matrix inversion which may lead to errors if the matrix is poorly conditioned. In this paper, we use the concept of theoretical continuous Loudspeaker on a circle to derive the discrete Loudspeaker aperture functions by avoiding matrix inversion. In addition, the aperture function obtained through continuous Loudspeaker method reveals the underlying structure of the solution as a function of the desired soundfield, the Loudspeaker positions, and the frequency. This concept can also be applied for the 3-D soundfield reproduction using spherical harmonics analysis with a spherical array. Results are verified through computer simulations.
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ICASSP - Soundfield reproduction using theoretical continuous Loudspeaker
2008 IEEE International Conference on Acoustics Speech and Signal Processing, 2008Co-Authors: Thushara D. AbhayapalaAbstract:Reproduction of a soundfield is a fundamental problem in acoustic signal processing. A common approach is to use an array of Loudspeakers to reproduce the desired field where the least square method is used to calculate the Loudspeaker weights. However, the least square method involves matrix inversion which may lead to errors if the matrix is poorly conditioned. In this paper, we derive a new theoretical continuous Loudspeaker method to obtain the Loudspeaker aperture function in order to avoid matrix inversion. In addition, the aperture function obtained through continuous Loudspeaker method reveals the underlying structure of the solution as a function of the desired soundfield, the Loudspeaker positions and the frequency.
Georgios B. Giannakis - One of the best experts on this subject based on the ideXlab platform.
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sound field reproduction using the lasso
IEEE Transactions on Audio Speech and Language Processing, 2010Co-Authors: G N Lilis, Daniele Angelosante, Georgios B. GiannakisAbstract:Reproducing a sampled sound field using an array of Loudspeakers is a problem with well-appreciated applications to acoustics and ultrasound treatment. Loudspeaker signal design has traditionally relied on (possibly regularized) least-squares (LS) criteria. In many cases however, the desired sound field can be reproduced using only a few Loudspeakers, which are sparsely distributed in space. To exploit this feature, the fresh look advocated here permeates benefits from advances in variable selection and compressive sampling to sound field synthesis by formulating a sparse linear regression problem that is solved using the least-absolute shrinkage and selection operator (Lasso). An efficient implementation of the Lasso for the problem at hand is developed based on a coordinate descent iteration. Analysis and simulations demonstrate that Lasso-based sound field reproduction yields better performance than LS especially at high frequencies and for reproduction of under-sampled sound fields. In addition, Lasso-based synthesis enables judicious placement of Loudspeaker arrays.
Etienne Corteel - One of the best experts on this subject based on the ideXlab platform.
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Practical 3 dimensional sound reproduction using Wave Field Synthesis, theory and perceptual validation
2012Co-Authors: Etienne Corteel, Lukas Rohr, Xavier Falourd, Khoa-van Nguyen, Hervé LissekAbstract:Sound field reproduction using Wave Field Synthesis has been so far limited to the positioning of virtual sources and listeners in the horizontal plane only. These simplifications were originally proposed to reduce the number of required Loudspeakers although the underlying formulation (Kirchhoff-Helmholtz) describes the reproduction of 3 dimensional sound fields in a 3 dimensional subspace. The authors propose here a revised formulation of Wave Field Synthesis in 3 dimensions that limits the number of required Loudspeakers, allowing for irregular and incomplete Loudspeaker layouts. A source width control parameter is further proposed to reduce localization blur using a virtual source dependent Loudspeaker selection criterion. The proposed approach is finally evaluated in an extended listening area. The experiment relies on an elevation localization comparison using individual Loudspeakers as targets and 3D WFS (with or without source width control) as pointer on a 24 channels Loudspeaker array that covers the frontal quarter of the upper half of a rectangular room.
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practical 3 dimensional sound reproduction using wave field synthesis theory and perceptual validation
Proceedings of the 11th French Congress of Acoustics and 2012 Annual IOA Meeting, 2012Co-Authors: Etienne Corteel, Lukas Rohr, Xavier Falourd, Khoa-van Nguyen, Hervé LissekAbstract:Sound field reproduction using Wave Field Synthesis has been so far limited to the positioning of virtual sources and listeners in the horizontal plane only although the underlying formulation (Kirchhoff-Helmholtz) describes the reproduction of 3 dimensional sound fields in a 3 dimensional subspace. However, a strict use of this formulation would require a surface Loudspeaker array with an impractical number of Loudspeakers. The authors propose here an optimized formulation of Wave Field Synthesis in 3 dimensions that account both for the limitation of localization accuracy of elevated sources and the target listening area size. In contrast to other 3 dimensional sound reproduction techniques such as Higher Order Ambisonics, the proposed approach allows for irregular and incomplete Loudspeaker layouts for targeting specific areas for virtual positioning and accounting for practical limitations in Loudspeaker positioning. The paper also proposes a subjective evaluation of the proposed approach in an extended listening area. The experiment relies on elevated physical sources (Loudspeakers) to be matched in localization with virtual sources reproduced with the proposed approach with a 24 channels Loudspeaker array that covers the frontal quarter of the upper half of a rectangular room.
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On the use of irregularly spaced Loudspeaker arrays for Wave Field Synthesis, potential impact on spatial aliasing frequency
2006Co-Authors: Etienne CorteelAbstract:Wave Field Synthesis (WFS) is a physical based sound reproduction technique. It relies on linear arrays of regularly spaced omnidirectional Loudspeakers. A fundamental limitation of WFS is that the synthesis remains correct only up to a corner frequency referred to as spatial aliasing frequency. This paper addresses irregular spacing of Loudspeaker array for WFS. Adapted driving functions are defined. New formulations of the spatial aliasing frequency are proposed. It is shown that the use of logarithmically spaced Loudspeaker arrays can significantly increase the spatial aliasing frequency for non focused virtual sources.
Hervé Lissek - One of the best experts on this subject based on the ideXlab platform.
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Practical 3 dimensional sound reproduction using Wave Field Synthesis, theory and perceptual validation
2012Co-Authors: Etienne Corteel, Lukas Rohr, Xavier Falourd, Khoa-van Nguyen, Hervé LissekAbstract:Sound field reproduction using Wave Field Synthesis has been so far limited to the positioning of virtual sources and listeners in the horizontal plane only. These simplifications were originally proposed to reduce the number of required Loudspeakers although the underlying formulation (Kirchhoff-Helmholtz) describes the reproduction of 3 dimensional sound fields in a 3 dimensional subspace. The authors propose here a revised formulation of Wave Field Synthesis in 3 dimensions that limits the number of required Loudspeakers, allowing for irregular and incomplete Loudspeaker layouts. A source width control parameter is further proposed to reduce localization blur using a virtual source dependent Loudspeaker selection criterion. The proposed approach is finally evaluated in an extended listening area. The experiment relies on an elevation localization comparison using individual Loudspeakers as targets and 3D WFS (with or without source width control) as pointer on a 24 channels Loudspeaker array that covers the frontal quarter of the upper half of a rectangular room.
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practical 3 dimensional sound reproduction using wave field synthesis theory and perceptual validation
Proceedings of the 11th French Congress of Acoustics and 2012 Annual IOA Meeting, 2012Co-Authors: Etienne Corteel, Lukas Rohr, Xavier Falourd, Khoa-van Nguyen, Hervé LissekAbstract:Sound field reproduction using Wave Field Synthesis has been so far limited to the positioning of virtual sources and listeners in the horizontal plane only although the underlying formulation (Kirchhoff-Helmholtz) describes the reproduction of 3 dimensional sound fields in a 3 dimensional subspace. However, a strict use of this formulation would require a surface Loudspeaker array with an impractical number of Loudspeakers. The authors propose here an optimized formulation of Wave Field Synthesis in 3 dimensions that account both for the limitation of localization accuracy of elevated sources and the target listening area size. In contrast to other 3 dimensional sound reproduction techniques such as Higher Order Ambisonics, the proposed approach allows for irregular and incomplete Loudspeaker layouts for targeting specific areas for virtual positioning and accounting for practical limitations in Loudspeaker positioning. The paper also proposes a subjective evaluation of the proposed approach in an extended listening area. The experiment relies on elevated physical sources (Loudspeakers) to be matched in localization with virtual sources reproduced with the proposed approach with a 24 channels Loudspeaker array that covers the frontal quarter of the upper half of a rectangular room.
G N Lilis - One of the best experts on this subject based on the ideXlab platform.
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sound field reproduction using the lasso
IEEE Transactions on Audio Speech and Language Processing, 2010Co-Authors: G N Lilis, Daniele Angelosante, Georgios B. GiannakisAbstract:Reproducing a sampled sound field using an array of Loudspeakers is a problem with well-appreciated applications to acoustics and ultrasound treatment. Loudspeaker signal design has traditionally relied on (possibly regularized) least-squares (LS) criteria. In many cases however, the desired sound field can be reproduced using only a few Loudspeakers, which are sparsely distributed in space. To exploit this feature, the fresh look advocated here permeates benefits from advances in variable selection and compressive sampling to sound field synthesis by formulating a sparse linear regression problem that is solved using the least-absolute shrinkage and selection operator (Lasso). An efficient implementation of the Lasso for the problem at hand is developed based on a coordinate descent iteration. Analysis and simulations demonstrate that Lasso-based sound field reproduction yields better performance than LS especially at high frequencies and for reproduction of under-sampled sound fields. In addition, Lasso-based synthesis enables judicious placement of Loudspeaker arrays.
