Fixed broadband beamformers using small-sized microphone arrays are known to be highly sensitive to errors in the microphone array characteristics. This paper describes a procedure for designing broadband beamformers with an arbitrary spatial directivity pattern, which are robust against errors in the microphone positions. The presented design procedure optimises the mean performance of the bro...

ABSTRACT We present a comparison of the measured and theoretical performance of a 24 microphone baffled circular microphone array. The signal-to-noise ratio of the circular microphone array is obtained by analysing the spatial aliasing error, the microphone placement error, and the white noise gain. The circular microphone array has a frequency range of operation from 50 Hz to 16 kHz, and we sh...

This paper presents a general method for the integration of distributed microphone arrays for localization of a sound source. The recently proposed sound localization technique, known as SRP-PHAT, is shown to be a special case of themore general microphone array integrationmechanism presented here. The proposed technique utilizes spatial likelihood functions (SLFs) produced by each microphone a...

A miniature differential microphone is described having a low-noise floor. The sensitivity of a differential microphone suffers as the distance between the two pressure sensing locations decreases, resulting in an increase in the input sound pressure-referred noise floor. In the microphone described here, both the diaphragm thermal noise and the electronic noise are minimized by a combination o...

In far-field speech recognition systems, training acoustic models with alignments generated from parallel close-talk microphone data provides significant improvements. However it is not practical to assume the availability of large corpora of parallel close-talk microphone data, for training. In this paper we explore methods to reduce the performance gap between far-field ASR systems trained wi...

This paper presents a numerical approach that projects frequency-dependent directivity patterns of classic recording microphones onto steerable beams created with a spherical microphone array. In an anechoic chamber, the spatial and timbral characteristics of a legacy recording microphone and the characteristics of a 120-channel spherical microphone array were measured. Using a least-square mat...