# How to extract a signal received from a given angle by two microphones

Please bear with me, as I'm only a programmer, and have no knowledge of signal processing as a discipline.

I have an application which generates a short pulse of 12 kHz frequency sound from a single central source, then captures any reflected sound with a pair of stereo microphones a few cm apart.

I want to be able to, effectively, scan across a range of angles, and extract the reflected sound at each angle, in order to build a picture of what is reflecting the sound. Essentially, sonar.

I've tried extracting the signal at different angles by sampling the incoming waveforms at different points corresponding to the time difference each angle would represent; but I'm not sure how to get something sensible from that. (I've tried calculating what I'm calling the correlation by dividing the absolute difference between the left and right signals and dividing by the maximum possible to normalise it; but all I seem to get, if I plot it, is noise).

I've spent a couple of days trying to find it online; but I'm hampered by my utter lack of knowledge of what even the most basic terms mean, and it's also a long time since I studied maths.

• Beamforming with only 2 microphones will probably not give you enough directivity for your application. The main reflection will probably flood al other values. Can you share any of your results so far? – Juancho Jul 6 '17 at 13:33