Effect of wall aperture on sound propagation within a tube

In this paper theoretical analysis of sound field within a tube with an apcrture on its wall is presented. Equivalent circuit is obtained for calculation of sound waves propagating within the tube. The aperture on tube wall can be represented by a lumped circuit impedance in the equivalent circuit. The impedance is written in terms of aperture impedance and an inertance due to the disturbance of sound field by the aperture. Expressions for calculation of the impedance are given for a rectangular aperture. The effect of sound source is also discussed.