Think of a video projector... now translate that to audio. Audio that follows you around when you walk, but doesn't disturb others.
“If you have audio going into a single speaker, it pours into a room like water. It just goes everywhere. Once we have multiple speakers under computer control, we can pre-distort the audio so that it builds up in some areas of the room and cancels itself out in others. We can do computer simulations of how the sound is going to propagate from the individual speaker cones and specify that we want more sound in one region and less sound in another.
Personal Audio Space: The Headphones Experience sans Headphones
First step is to catch up to "state of the art". Second step is to blow right on by.
“The way I like to design research projects,” Droppo says, “is that each phase answers at least one or two questions that we don’t know [the answer to]. While we don’t have anything spectacularly different yet, in the past few months, we’ve been able to catch up to the state of the art, and the real exciting part for me is where we’re taking this in the future.”