The Diffuse Field Theory of sound propagation indoors, embodied in the formula,[Lp = Lw + 10 log(Q/4πr2 + 4/A)], does not work well for typical furnished rooms in dwellings and offices. An alternative simple empirical relationship has been found that predicts with considerable accuracy the sound pressure level in such rooms, based on the sound power level of the source, the room volume, the frequency, and the distance from the source:Lp = Lw − 10 log r(ft) − 5 log V(cu ft) − 3 log f(Hz) + 25 (dB). If this new relationship is accepted, there are serious implications for our current standard test procedures for field measurements in occupied buildings. Since the room absorptionAdoes not appear explicitly in the formula, the customary normalization with terms like 10 logAin transmission loss and impact noise field tests is probably incorrect. In addition, since no uniform reverberant sound field occurs in normally furnished dwelling and office spaces, it is not clear what one ought to measure for the receiving‐room sound pressure level in field tests of transmission loss, noise reduction, and impact noise. [Work supported by ASHRAE.]