The image method, developed by Allen and Berkley in 1979, is probably one of the most commonly used methods in the acoustic signal processing community to create synthetic Room Impulse Responses. A mex-function, which can be used in Matlab, has been created to generate multi-channel Room Impulse Responses using the image method. This function enables the user to control the reflection order, room dimension and microphone directivity.
The signal generator is a mex-function for MATLAB. It can be used to generated the response of a moving sound source and receiver in a reverberant environment. The user can specify the position of the source and the receiver at each discrete time instance. The generated output signal is computed by convolving the (anechoic) source signal with the time-varying room impulse response. Multiple receiver positions can be specified to generate multiple responses simultaneously. The room impulse responses are generated using the image method, proposed by Allen and Berkley in 1979. The user can control the reverberation time (or reflection coefficients), reflection order, room dimension and microphone directivity in a way similar to the RIR generator. This package includes a MATLAB example, the mex-function, and the source code.
A method is proposed for simulating the sound pressure signals on a spherical microphone array in a reverberant enclosure. The method employs spherical harmonic decomposition (SHD) and takes into account scattering from a solid sphere. An analysis shows that the error in the decomposition can be made arbitrarily small given a sufficient number of spherical harmonics.
Two methods were proposed to generate multi-channel noise signals with a specific spatial coherence. The first method is designed to generate stationary noise signals that are observed in an ideal cylindrically or spherically isotropic noise field, while the second method is designed to generate noise signals with an arbitrary spatial coherence. The second method is particularly useful to generate multi-channel babble speech signals.