This is a first Ive heard about for consumer use. I had heard about the military use. It will be nice if they perfect it for the boating industry. To be able to have clear music 60+ ft back behind the boat, at a reasonable cost, would be great.
typically it is an array of point sources that they vary the phase to 'steer' the sound. due to the physical nature of the world it doesn't mean the sound doesn't go elsewhere as well.