Sound localization with Raspberry pi

On Thursday, 14 August 2014 23:49:44 UTC+3, Tareq Matar  wrote:
> I want to use the RPI to process the incoming data from five crystal micr=
ophones in order to obtain the direction of arrival of sound so that i can =
steer a camera mounted on two servos to that direction.
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> Since there is no audio inputs to the RPI i think of using a two-channel =
analog to digital converter, one channel is connected to a refrence mic and=
 the other channel is connected to the output of a 4-1 analog multiplexer c=
onnected to the other four mics.
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> Is it the right way to do my project? if not then how do i do it ?
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> is there a recommended 2channel ADC and 4-1 analog mux compatible with th=
e RPI?

this is the design im thinking of:

1 refrence mic >----->pre-amp>---------------------> ADC >----> RPI >---> s=
ervos
other mics >--------->pre-amp>---->analog MUX>----->ADC >-----> RPI >---->s=
ervos

and since im using the Steered Response Power - Phase Transform(SRP-PHAT) i=
 only need to calculate the cross-correlation between each independent pair=
 of mics, find the time difference of arrival and finally evaluate the dire=
ction of arrival.

am i missing any thing? do i have to do some beamforming techniques? e.g. d=
elay-and-sum, filter-and-sum, etc.