The probability distribution of pressure amplitudes in a room is studied theoretically and experimentally. A point source is assumed to emit a Poisson sequence of pulses. The method of cumulant generating functions is used to obtain the distribution of response in the direct field, the reverberant field, and the transition region. In the direct field, the source statistics are reproduced. For sufficiently reverberant spaces, the reverberant field tends to normality independently of the source distribution. For sufficiently short pulses (or short autocorrelation time of the source) the direct and reverberant fields are statistically independent. When these simplifying conditions are not met, we indicate how the results may be generalized. Implications for calculations of random fatigue and component malfunction are discussed briefly.