Existing methods for determining the sound absorption in rooms usually require some knowledge of the room dimensions. If sound-pressure-level measurements are made at various distances from a small source (such measurements herein referred to as a walk-away test) the room sound absorption can be deduced provided the variation of sound pressure level with distance can be described by the simple equation SPL=PWL (sound power level)+10 log10(Q/4πr2+4/A′), which is commonly credited to Beranek. Unlike the reverberation time and estimated area methods (𝒥Siαi), a walk-away test can be used to determine the room absorption where either the room volume or wall areas and the absorption coefficients are uncertain or for rooms which are acoustically coupled to other rooms.