This is just a signal processing technique applied to sound instead of a phased array radar. (Where it probably gets vastly more funding.) Guarateed the technique was matured in the military/DoD realm. It's called beam steering, and depending on the hardware configuration you can generate multiple beams.
There's a serious problem with applying it to sound though, as opposed to radar. Basically, sections of the array are used to form individual beams, and a delay is added (at each transmitter in the array) to the signal to "steer" (and shape, although the potential patterns are largely affected by transmitter design) the wavefront by using constructive and destructive interference. Anyway the complication comes in because of the range of frequencies involved. Radars operate in a (relatively small) region around some center frequency, so the beam steering is simplified somewhat. To do this with sound, the delay would have to take into account the frequency, so it gets significantly more complicated.
As for the capabilities of phased array radars that the US has currently, with respect to things like Aegis, I don't really know what I can say so just search around online and I'm sure you'll find some interesting stuff.
