On directivity of a circular array with directional microphones

Circular microphone arrays have a broad range of applications in teleconferencing and hands-free telecommunication systems. Directional microphones are extensively used to construct the circular arrays to obtain superior sound quality. However, the 360-degree coverage ability of this type of circular arrays is seldom investigated. In this paper, we develop a circular array with the use of four firstorder supercardioid microphones to obtain 360-degree coverage of sound recording in teleconferencing environments. Through analyzing the directional response of this array, we derive an optimal range of the array radius for uniform 360-degree coverage of sound capturing. Experiments are carried out in an anechoic chamber to test the performance of the developed microphone array.

1. Introduction

Microphone arrays, which are used to capture sound signals, are extensively employed in voice communication systems, noise control systems, and machine learning systems [1]–[3]. Commonly used arrays include linear, circular, planar, spherical, and distributed configurations. Among these configurations, circular arrays can work in full circle range to capture sound signals from 360-degree azimuth, and so they are widely employed in teleconferencing systems. This paper is concerned with this type of arrays.