Uncertainty in Room Acoustics Measurements

This chapter provides an overview for those undertaking room acoustics measurements, calculations and modelling for practical purposes. It is a practical guide, with references to acoustic theory and international standards where necessary. The chapter discusses room acoustic parameters used in performance spaces and described in part 1 of ISO 3382. It has also included a discussion of measurements using the “new measurement methods” described in ISO 18233 (2006). Although more a signal-to-noise ratio than a room acoustic measurement, it is certainly affected by room acoustics, and anyone using room acoustics parameters as part of an STI prediction should take account of the uncertainties described in the chapter. In room acoustics, we have to start by generating a suitable signal over which we have at least some control. Probably the most commonly used signal for measurement of reverberation time in ordinary rooms is interrupted random noise played through a loudspeaker.