On the accuracy of sound pressure level measurements in rooms

When measurements are made of the average sound pressure level in a room there will be an error because of the finite number of positions at which measurements are taken. However, if the standard deviation of the readings and the number of samples are known then an estimate of the accuracy can be made. It is shown that the standard deviation can be predicted with both bandlimited and broadband excitation. It is also shown that for many practical situations it can be assumed that the probability distribution of the dB readings is normal, and that this greatly simplifies the calculation of confidence intervals. © 1990.