We show an approach to localizing an acoustic source using a circular microphone topology. Consider the circular array illustrated in Figure 1 below and suppose the angle of arriving signal,, and the range , are desired. Note that these two parameters, , taken together allow for precise source localization.
Figure 1: Circular microphone array topology for microphones,
Define the angle of arrival to be the impinging angle at microphone as , using the line joing micrphones and as reference. Then the microphones can be easily shown to obey;
where is the time difference of arrival between the signals at microphones and .
The least squares solution to solve the angle of arrival, , thus:
VOCAL Technologies offers custom designed solutions for beamforming with a direction of arrival estimation, robust voice activity detector, acoustic echo cancellation and noise suppression. Our custom implementations of such systems are meant to deliver optimum performance for your specific beamforming task. Contact us today to discuss your solution!