The reconstruction and reproduction of sound fields have been extensively researched in the last decades leading to an intuitive approach to evaluate the acoustic properties of an environment. Applications of Auralization can be found in areas such as room and environmental acoustics, noise control, virtual reality, training and video games among others.
Auralization may be created using different methodologies to synthesize the impulse response, the most common of them, the use of geometrical acoustics and methods based on the numerical solution of the wave equation. The assumptions and limitations of each approach are well known, which in turn, restrict their application to a specific frequency range. If the aim is to reconstruct the sound field in the entire human hearing range, a combination of these methodologies has to be performed. Furthermore, recent advances in computational power have enabled the possibility to generate interactive atmospheres where the user is able to interact with the environment. This feature, although expands the applications of the Auralization, it is nowadays mainly based on Geometrical Acoustics methods.
The present research addresses the generation of interactive broadband Auralizations of enclosures using a combination of Finite Element Methods and conventional Geometrical Acoustic methods. For this, considerations regarding to the characterization of acoustic source, level of geometrical detail in the models and the boundary conditions are discussed. Then, the predicted room impulse responses are represented as a finite superposition of plane waves, which in turn, enables some interactive features as translation and rotation of the sound field. Moreover, the Plane Wave Expansion of the sound field allows the implementation of several sound reproduction techniques increasing the versatility of this approach. This methodology enables the reconstruction of the aural impression of enclosures with better accuracy at low frequencies allowing interactive features.
Diego Murillo Gomez, Filippo Fazi