I did hear mention of the idea that different language versions of the same audio could be delivered to different people in the same room at the same time without either party hearing the other language. Personalised beams are just an amazing concept. I also heard that by using the ultrasonic emission from the chip a directional mic could track where each different listener was by echo detection and keep the beams pointed at them. If even half of these things prove practical we are dealing with future tech of a high order!
I worked for 3M for a while, and they had just introduced a visual filter that could fit on top of a computer screen, such as the ones built into cashcard machines or the like. The screen contained a microscopic 'Venetian blind' array that ensured what was on the screen was only viewable from directly in front of the device. This ensured nobody else could see what you were reading. These are still available I think. At the time we asked if the same could be done for the sound, and we were told that was a harder problem because sound from a speaker came out in all directions and bounced off everything, and making a tight sound beam was very difficult with conventional technology.
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