That's the possibility presented by “sound beaming,” a new futuristic audio technology from Noveto Systems, an Israeli company On Friday it will debut a desktop device that beams sound directly to a listener without the need for headphones.
~ https://www.digitalmusicnews.com/2020/11/13/sound-beaming-tech-3d-audio/ (https://www.digitalmusicnews.com/2020/11/13/sound-beaming-tech-3d-audio/)
Imagine a world where you move around in your own personal sound bubble. You listen to your favorite tunes, play loud computer games, watch a movie or get navigation directions in your car — all without disturbing those around you.
~ https://www.billboard.com/articles/news/9483846/soundbeamer-music-in-your-head-no-headphones/ (https://www.billboard.com/articles/news/9483846/soundbeamer-music-in-your-head-no-headphones/)
Hardly new, not that facts ever mattered much when marketing. It uses ultrasound at an intensity great enough for air to behave nonlinearly, transmitted from a phased array so it can track your ears.
I vaguely remember an article about a company (Marantz?) doing something similar in the early Nineties. Something about using it in museums and galleries, so you didn't need to have a headset for the audio guidebook.
I think this get tried every 10 years or so, but it never seems to produce a practical device. Presumably the (highly nonlinear) downconversion of ultrasound to regular acoustic frequencies doesn't lend itself to high audio quality.
I've just been using an Aeropex from Aftershokz bone conduction headset at work, which would cover most or all individual consumer-based usage (i.e. not in public places like museums, etc.). Seems like a FAR simpler solution and a lot more versatile and I'll bet quite a lot less expensive. I even use it in the shower sometimes. I like it so much (except mic quality - I think it might be using the old narrowband Bluetooth HFP) that I bought another one just to keep in my work bag.
This sound beaming thing looks to be extremely convoluted for such a mundane thing you can mostly do by other means. I'll deal with a head-tracking rig for something for which other stuff is not feasible, like the Realiser A16.