This paper presents an extension of the standing-wave model of interference tubes for microphones by Ono et al. The original model accounts for three acoustic parameters: tube length, tube radius, and constant acoustic conductance per unit length. Our extension allows a varying conductance per unit length along the side wall. The assumptions behind the extended model and its ability to predict the frequency response of interference tubes are validated through simulations and by fitting the model parameters to frequency response measurements of a tube with varying conductance per unit length, using two different mountings. Results suggest that a tube with varying conductance per unit length is most effective at attenuating the off-axis sound if the conductance per unit length is decreased towards the tail end of the tube.
|Title of host publication||Proceedings of 145th Audio Engineering Society Convention|
|Publisher||Audio Engineering Society|
|Publication status||Published - 2018|
|Event||145th International Pro Audio Convention - Jacob K. Javits Convention Center, New York, United States|
Duration: 17 Oct 2018 → 20 Oct 2018
|Conference||145th International Pro Audio Convention|
|Location||Jacob K. Javits Convention Center|
|Period||17/10/2018 → 20/10/2018|
Bigoni, F., Agerkvist, F. T., & Bøgh, E. (2018). A Stepped Acoustic Transmission Line Model of Interference Tubes for Microphones. In Proceedings of 145th Audio Engineering Society Convention  Audio Engineering Society.