Ascertaining confidence within the ray-tracing method

The Monte Carlo method is applied to the ray-tracing method to obtain an er ror measure of the sound energy hitting a receptor during a time interval. Simple geometrical interpretations are introduced to guide the equation dev elopment. The variance measurement method introduced a few years ago as an error indicator for the ray-tracing technique is analyzed and compared with the new method. It is shown that the previous method cannot be considered either an error measure or an error estimator, and that the new one provide s a consistent answer to many simulation problems. The effects of wall abso rption, reverberation time, elapsed time, and integration interval in both formulas are evaluated. (C) 1999 Acoustical Society of America. [S0001-4966 (99)06007-5].