Source excitation strategies for obtaining impulse responses in finite difference time domain room acoustics simulation

Recent work on excitation mechanisms in acoustic finite difference models focuses primarily on physical interpretations of observed phenomena. This paper offers an alternative view by examining the properties of models from the perspectives of linear algebra and signal processing. Interpretation of a simulation as matrix exponentiation clarifies the separate roles of sources as boundaries and signals. Boundary conditions modify the matrix and thus its modal structure, and initial conditions or source signals shape the solution, but not the modal structure. Low-frequency artifacts are shown to follow from eigenvalues and eigenvectors of the matrix, and previously reported artifacts are predicted from eigenvalue estimates. The role of source signals is also briefly discussed.

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“…1 and 2, or mode shift reported in Ref. 21. A similar, but unrelated, DC solution component is linear DC drift in models with rigid boundaries.…”

Section: Effect Of Hard Sourcesmentioning

confidence: 86%

Effects of sources on time-domain finite difference models

Botts

Savioja

2014

The Journal of the Acoustical Society of America

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“…Some researchers investigated the use of various source models. Other researchers [9][10][11] investigated sourced excitations in the finite-difference time-domain method. Escolano et al [12] proposed the use of a M A N U S C R I P T…”

Section: Wave-based Acoustical Methodsmentioning

confidence: 99%

Recent advances in building acoustics: An overview of prediction methods and their applications

Mak

Wang

2015

Building and Environment

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“…14 the wall filter response is plotted together with the corresponding Sabine predictions in (34), which for the given room becomes (37) The simulated RIR was fed into an octave-band filter bank, and values were calculated for each octave-band. As shown in Fig. 14, these measured are very close to Sabine's formula prediction, thus confirming that the proposed model allows controlling the absorption behavior of wall materials explicitly.…”

Section: A Reverberation Timementioning

confidence: 99%

Efficient Synthesis of Room Acoustics via Scattering Delay Networks

Sena

Hacıhabiboğlu

Cvetković

et al. 2015

IEEE/ACM Trans. Audio Speech Lang. Process.

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An acoustic reverberator consisting of a network of delay lines connected via scattering junctions is proposed. All parameters of the reverberator are derived from physical properties of the enclosure it simulates. It allows for simulation of unequal and frequency-dependent wall absorption, as well as directional sources and microphones. The reverberator renders the first-order reflections exactly, while making progressively coarser approximations of higher-order reflections. The rate of energy decay is close to that obtained with the image method (IM) and consistent with the predictions of Sabine and Eyring equations. The time evolution of the normalized echo density, which was previously shown to be correlated with the perceived texture of reverberation, is also close to that of IM. However, its computational complexity is one to two orders of magnitude lower, comparable to the computational complexity of a feedback delay network (FDN), and its memory requirements are negligible

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Source excitation strategies for obtaining impulse responses in finite difference time domain room acoustics simulation

Cited by 34 publications

References 15 publications

Effects of sources on time-domain finite difference models

Effects of sources on time-domain finite difference models

Recent advances in building acoustics: An overview of prediction methods and their applications

Efficient Synthesis of Room Acoustics via Scattering Delay Networks

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