Room acoustics: Idealized field and real field considerations (original) (raw)
Related papers
Beam-Tracing Prediction of Room-To-Room Sound Transmission and the Accuracy of Diffuse-Field Theory
Acoustics Week Canada Proceedings, Canadian Acoustical Association (CAA), 2017
This paper validates the applicability of the classical diffuse-field prediction formula of room-to-room sound transmission used by many practitioners using energy- and phase-based beam-tracing models. An existing beam-tracing model for empty, parallelepiped rooms with specularly-reflecting surfaces has been adapted to predict room-to-room sound transmission between source and receiver rooms separated by a common partition. For simplicity, initially sound transmission through the homogeneous common wall is modelled as one locally-reacting homogenous partition with frequency-independent transmission loss. The energy-based beam-tracing model has been validated in both source and receiver rooms through existing results from ODEON in the literature and by comparing the prediction results with CATT-Acoustic room-to-room sound transmission model. The phase-based beam-tracing model has been validated in the source room in comparison with COMSOL predictions. The new models are then used to ...
The room acoustic rendering equation
2007
An integral equation generalizing a variety of known geometrical room acoustics modeling algorithms is presented. The formulation of the room acoustic rendering equation is adopted from computer graphics. Based on the room acoustic rendering equation, an acoustic radiance transfer method, which can handle both diffuse and nondiffuse reflections, is derived. In a case study, the method is used to predict several acoustic parameters of a room model.
Comparison of an integral equation on energy and the ray-tracing technique in room acoustics
The Journal of the Acoustical Society of America, 2000
This paper deals with a comparison of two room acoustic models. The first one is an integral formulation stemming from power balance and the second is the ray-tracing technique with a perfectly diffuse reflection law. The common assumptions to both models are the uncorrelated wave hypothesis and the perfectly diffuse reflection law. The latter allows the use of these methods for nondiffuse fields beyond the validity domain of Sabine's formula. Comparisons of numerical simulations performed with the softwares RAYON and CeReS point out that these results are close to each other and finally, a formal proof is proposed showing that both methods are actually equivalent.
2004
A new approach for the analysis of high-frequency broadband reverberant sound fields in rooms with diffuse reflection boundaries is described. Depending on shape, source location, and the distribution of wall absorption, rooms exhibit spatial variation in steadystate mean-square pressure and also spatial dependence of decay time characteristics. It is shown that the room boundaries can be replaced by a distribution of uncorrelated broadband directional energy-intensity sources. In steady state with diffuse reflection boundaries, the interior pressure field produced by these sources satisfies Laplace’s equation. This fact allows the mean-square pressure field to be re-expressed as a sum of constituent modes. The corresponding intensity field, which is related to the pressure field in a complex way, can be calculated in closed form for each of these modes. Wall boundary conditions relate the intensity and pressure fields. The mean-square pressure solution is expressed in terms of the ...
19th INTERNATIONAL CONGRESS ON ACOUSTICS MADRID, 2-7 SEPTEMBER 2007
ABSTRACT Room acoustics can be modeled by simulating the propagation of acoustic energy in the space under consideration. Thus, it is possible to formulate a room acoustic rendering equation which perfectly describes the time-dependent distribution of the energy. The current room acoustics modeling methods can be derived as special cases of this equation. In addition, an acoustic radiance transfer method has been constructed for modeling the sound propagation in environments with arbitrary reflection properties.
A Theoretical Approach to Room Acoustic Simulations Based on a Radiative Transfer Model
A theoretical approach to room acoustic simulations based on a radiative transfer model is developed by adapting the classical radiative transfer theory from optics to acoustics. The proposed acoustic radiative transfer model expands classical geometrical room acoustic modeling algorithms by incorporating a propagation medium that absorbs and scatters radiation, handling both diffuse and non-diffuse reflections on boundaries and objects in the room. The main scope of this model is to provide a proper foundation for a wide number of room acoustic simulation models, in order to establish and unify their principles. It is shown that this room acoustic modeling technique establishes the basis of two recently proposed algorithms, the acoustic diffusion equation and the room acoustic rendering equation. Both methods are derived in detail using an analytical approximation and a simplified integral equation of the proposed method, respectively, allowing a clear definition of the underlying assumptions, limitations, advantages and disadvantages