An isotropic sound field model composed of a finite number of plane waves

Isotropy is a fundamental property of diffuse sound field. Although several studies have proposed an isotropy indicator to quantify the extent field, what not yet very clear how interpret quantified using these indicators. This study aims contribute understanding by (i) modifying existing based on spherical harmonic expansion and (ii) presenting isotropic field model composed finite number plane waves. Theoretical numerical investigations show that limited-degree can be established model.