John, now you have the imaging device, it would be a simple matter to build a telescope, your choice of Newtonian, or refractor (get some bin bags full of heavy gases and make them into lens shapes)

Could this be used to get the projected location of the sound in 3d space relative to the receiver? I've had an idea for a self pointing light source that responds to finger snaps and have thought about a phased array before but I haven't had a large amount of time to investigate them other than in a precursory look

Im going to have to disagree with your username :), but yeah, it should be able to do basic angle-of-arrival.  But, you could probably do that with a lot fewer microphones, like is done in an amazon echo. I know seeed has (or at least had) an array for that kind of direction finding. 

You only need this many to get the gain and bandwidth to do imaging over many frequencies, with reasonably non-blurry images.

"mainly just a platform to mess around with beamforming and general phased array and signal processing math"

No further justification necessary, your honor!

Marvelous project. 

Can you see reflections off of walls from the point sources?  It would be so cool to see how an impulse bounces around in a room.

Thanks!

Yes! reflections were one of the coolest things to see with this, pointing it at a corner of my room even acted like a corner reflector!  In some of the later tests you could even see sound going through things, and diffracting around edges.

I eventually added some processing to take barker coded impulses and do 3D mapping, but still needs a LOT of work to get the processing to produce useful images/videos.  Havent had much time the last couple months, just moved twice and started a new job, but planning to get back on this at some point.

Most impressive project I've seen in a while. Great video. 

Thanks!