This is a technology I had heard about a while ago, it was demonstrated in some “future car options” blurb. It is focused sound.
We can focus light in tight groupings, and we call it lasers, or a little looser grouping and we call it a spotlight. For audio, we have (so far) pretty much only had a wide-angle lens, or unidirectional sound. But this technology can focus sound waves into a very small area. This sound can be transmitted at very little volume drop over long distances, and the people that aren’t in the direct beam won’t even hear it.
It’s a great thing that I can’t wait to see in practice. The article above shows how it can create directional sound without having to have rear or side speakers. The original article I had read indicated it was going to be used so that multiple people in a car could listen to different radio stations without disturbing the other occupants.
