And it's about time someone did it! Yours is the first hobbyist project I've encountered since my own extremely crude ten-dollar version in 1981. No square array or processing, mine was a mechanical scanner-disk: eight LEDs glued in a spiral to an old vinyl record album, each with an electret microphone and and op amp. Spin the disk with a motor at about 6Hz. Wind noise, so add foam to the mics. It worked. A mechanical acoustic-phosphor raster sensor and display screen, where sound patterns caused light patterns. The best part was to hold some headphones near it while playing 10KHz sine wave. This produced interference stripes on the scanning disk! I hoped to build a huge version someday, but somebody beat me to it: Tom Zimmerman, an MIT student who patented the dataglove, then used the money to work at Exploratorium Museum for a year (as Artist in Residence), building a scanning-microphone LED disk about 6ft wide.
Since then we have companies selling DIDSON full-blown video for underwater (with sonic illumination,) also a euro company with a 3D phase-array microphone imager positioned on a ring or a wire sphere. See:
http://www.soundmetrics.com/Image-Gallery/Fisheries/Habitat-...
Heh, the divers appear to be skeletons wearing scuba tanks.
http://www.acoustic-camera.com/en/products/microphone-arrays...