Towards validating the diffraction-enhanced image source method

Accurately simulating room acoustics between directional sources and receivers in reverberant environments can be challenging. Wave-based numerical models can be used at low frequencies, but at higher frequencies, the cost of solving these models is often too prohibitive to permit practical use. Geometrical models can be used to simulate sound fields in rooms at higher frequencies but with limited accuracy due to the inherent assumptions made when deriving the models. Therefore, there are ongoing efforts within the room acoustics community to improve the accuracy of geometrical models. Recently, an extension to the image source method called the diffraction-enhanced image source method, which uses spherical harmonic descriptions to include directional sources and receivers, has been proposed. The proposed method can be used to efficiently model sound fields in shoebox-shaped rooms with directional sources and receivers at high frequencies. In this paper, predictions of the proposed method are compared to data measured in a shoebox-shaped room. It is shown that the proposed method captures many of the pertinent features of the measured transfer functions and impulse responses.