Overview of geometrical room acoustic modeling techniques

Abstract

Computerized room acoustics modeling has been practiced for almost 50 years up to date. These modeling techniques play an important role in room acoustic design nowadays, often including auralization, but can also help in the construction of virtual environments for such applications as computer games, cognitive research, and training. This overview describes the main principles, landmarks in the development, and state-of-the-art for techniques that are based on geometrical acoustics principles. A focus is given to their capabilities to model the different aspects of sound propagation: specular vs diffuse reflections, and diffraction.

The Wave-Matching Boundary Integral Equation — An energy approach to Galerkin BEM for acoustic wave propagation problems

“…Hence a set of smaller, geometrically-detailed models could feed scattering data into a larger, geometrically-idealised model based on the proposed method. This approach of replacing a geometrically complicated boundary with a simpler one and some scattering data is well established within geometrical acoustic methods [7].…”

“…Despite these advantages and the success of BEM in these areas, it is undeniable that almost all acoustic practitioners, particularly in room acoustics, select geometrical acoustic modelling techniques [7], such as ray-tracing, beam-tracing and image source, over approaches such as BEM that solve the Helmholtz or scalar wave equations directly. Partly this is likely due to accumulated expertise in applying these methods and the availability of material data, though the latter is almost always estimated and is widely acknowledged to be a source of inaccuracy [8].…”

Room acoustics: Idealized field and real field considerations

“…Methods for automatic signal generation that combine sound signals in order to obtain desired spectral and temporal characteristics were developed by Accolti and Miyara (2015) and methods that can also obtain desired signal to noise ratios depending on frequency were developed by Accolti et al (2017b). The required measures can be obtained with questionnaires and auralization techniques (Vorländer, 2008), ray acoustics models (Savioja and Svensson, 2015), or wave equation models (Kuttruff, 2000) according to the application and in turn to the particular definition of the diffuse field.…”

“…While identifying the direct sound and the first reflections in Figure 6 is straightforward, identifying the late reflections is hard because they are too close between them. A detailed review on current methods of geometrical room acoustics modeling can be found in Savioja, L. and Svensson, 2015. Each reflection and also the direct sound have well defined directions.…”

Auralization of Accelerating Passenger Cars Using Spectral Modeling Synthesis

“…Auralization has been in use for quite some time in architectural acoustics, namely in the fields of room and building acoustics [1][2][3], but it has only recently been discovered for environmental acoustical applications. Today, most auralizations are generated based on computer models and digital signal processing.…”