Can't wait till rogue arrays of lasers start beaming advertisements directly into your ear while walking down the street.
They used this in an ad in New York in 2007 for the TV series "Paranormal State", which was premiering soon on A&E. It was a paranormal themed reality show. They had a big billboard for the series on the side of a building, and Holosonic's "audio spotlight" technology on the roof that sent two beams of modulated ultrasound down to the sidewalk.
Pedestrians who walked directly into the beams would hear a disembodied voice whispering creepy things like "Who's there? It's not your imagination", but someone next to them who didn't enter the beam would hear nothing. Here's a video [2].
Here's an article about that ad campaign, and it also mentions some other ad uses of the technology [3]. Interesting quote from it:
> Joe Pompei, president and founder of Holosonics, said the creepy approach is key to drawing attention to A&E's show. But, he noted, the technology was designed to avoid adding to noise pollution. "If you really want to annoy a lot of people, a loudspeaker is the best way to do it," he said. "If you set up a loudspeaker on the top of a building, everybody's going to hear that noise. But if you're only directing that sound to a specific viewer, you're never going to hear a neighbor complaint from street vendors or pedestrians. The whole idea is to spare other people."
[1] https://en.wikipedia.org/wiki/Sound_from_ultrasound
Edit: I also wonder how it works if you modulate or otherwise moderate the interface between ear surfaces and ear-surroundings moisture, since that's apparently the resource this method needs in order to work at all. Shopping with headphones on can be a pretty nice experience IMO, and maybe it doubles as a countermeasure.
People annoying other people with laser pointers is going to become _so_ much more annoying.
True. Antisocial behaviour gets orders of magnitude worse and more prevalent once you can actually make money with it.