In The Optical Society (OSA) journal Optics Letters, researchers from the Massachusetts Institute of Technology's Lincoln Laboratory report using two different laser-based methods to transmit various tones, music and recorded speech at a conversational volume.
"Our system can be used from some distance away to beam information directly to someone's ear," said research team leader Charles M. Wynn. "It is the first system that uses lasers that are fully safe for the eyes and skin to localize an audible signal to a particular person in any setting."
That means the messages can be targeted.. to specific people.. voices in your head may be purposely on their way..
MORE : https://phys.org/news/2019-01-technology-lasers-transmit-audible-messages.html