Sound Transmission through Rectangular Slots of Finite Depth between Reverberant Rooms

Abstract

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.