Researchers at MIT have developed a new technology that will allow an audio transmission using lasers to be beamed straight into a person’s ear.
The research was published at the end of January and explains that the technology can transmit sound at 60 decibels – a normal conversation level – to a person standing around 2.5 metres away. Even though this will sound no louder than a coffee shop chat, researchers have already identified several uses for this technology, most of which relates to the security sector. More specifically, being able to send messages to personnel in a room full of people. Cue James Bond jingle.
The science behind the technology offers an interesting read but here’s the TL;DR version. When light is absorbed by a material, sound waves are formed, and this is called the photoacoustic effect. Researchers took these principles and applied it to the water vapour that’s in the air around us. Using lasers, they can make the water vapour in the air absorb light, thus creating audible sound that you can hear.
“This can work even in relatively dry conditions because there is almost always a little water in the air, especially around people,” said research team leader Charles M. Wynn. “We found that we don’t need a lot of water if we use a laser wavelength that is very strongly absorbed by water. This was key because the stronger absorption leads to more sound.”
Now before you ask, the research also points out that the this is the first system that uses lasers that are safe for your eyes.
It may still be a few years before we see laser audio gaming headphones or laser-based silent discos, but we can dream so long, can’t we?