Sound Transmission through Rectangular Slots of Finite Depth between Reverberant Rooms

An approximate theoretical relationship has been developed for the transmission of sound between two reverberant rooms through a connecting rectangular slot of finite depth. The theory makes use of impedance functions of rigid weightless rectangular pistons and assumes plane‐wave propagation through the slots. Slots having aspect ratios of 1, 2, 4 and 8, and depth of 12 in., were tested between two 1750‐ft³ reverberation chambers. Three different slots for each aspect ratio were tested, and the slot dimensions were so chosen as to have the cross‐sectional areas π/4, π, and 4π in.² in each case, to compare with previously published results on circular apertures having these areas. Numerical solutions on a digital computer are compared with experimental results and the agreement is found to be excellent over the range of the parameter—wavenumber times equivalent radius of a circular section having the same area as the rectangular section—from 0.05 to 3.2.