Image model for computer simulation of sound wave behavior in an enclosure

An image model using the ray tracing method has been developed to calculate the multipath in an enclosure up to a prescribed order of images. Non-uniform wall reflectivities can be included. For the special case of rectangular enclosures, the algorithm efficiently calculates the incident angle for each arriving signal and its associated reflection points. The performances of gradient microphones in an enclosure can be evaluated. It is noted that the number of images for a given order more nearly resembles an arithmetic series instead of a geometric series. The model is also extended to calculate the impulse response when obstacle planes are inside the enclosure.