Study of DIF Boundary Model with Rectilinear FDTD Scheme in Voice Booths
* Presenting author
Computational simulations are helpful when studying acoustical properties of rooms. This represents a challenge when very small rooms, such as office video/phone booths, are taken into account. The volume of these rooms generally does not exceed 15 m³ and the first modes occur at higher frequencies if compared to larger rooms. Computational room acoustics considers two main techniques of modelling sound propagation: geometrical and wave-based. As geometrical modelling is not the most suitable approach for low frequencies since the phase performs an important part in the physics at this frequency range, in the present study, a rectilinear FDTD scheme routine was implemented to obtain the impulse responses for low frequency bands of a voice booth, using proper boundary conditions derived from digital impedance filters (DIF). In order to obtain wideband impulse responses, high frequency impulse responses were acquired using a commercial software based on geometrical methods. Both responses were later filtered with low-pass and high-pass filters based on Schroeder frequency, and then assembled. The results were compared with data obtained from field measurements and, finally, listening tests were carried out to compare stimuli obtained from auralized and recorded impulse response of the room.