Propagation phase and zeros in the complex frequency plane

Abstract

This paper describes the transfer function (TF) including the coherent sound field as the distance between source and observation points increases, from a point of view of the number of zeros on a complex frequency plane. The propagation phase could be estimated according to the linear-regression analysis for narrow frequency-band frequency characteristics of the minimum-phase component [Inst. Electron. Inf. Commun. Eng. Jpn., J89-A(4) 291–297 (2006) (in Japanese with English figures)]. This paper analyzes zeros of the TFs for the coherent and reverberant fields based on the modal and random sound field theory. Consequently the distribution of zeros could be estimated in the transition from the coherent to the reverberant conditions.