MIT Researchers Use Laser to Transmit Sound into People’s Ears


How does this work?
How do the receivers look like?
Is it similar to what provides?

MIT Researchers Use Laser to Transmit Sound into People’s Ears

January 30, 2019Brian Taylor Leave a comment

Laser technology has been used for several decades and has a wide of applications, including bar code scanning, Lasix eye surgery, and industrial cutting and engraving. Now, laser might be used in hearing technology. 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.

The MIT researchers demonstrated that a laser can transmit an audible message to a person without any type of receiver equipment in the ear canal. The findings, under the direction of lead author Charles Wynn, were published in The Optical Society journal, Optics Letters .

The new approach is based on the photoacoustic effect, which occurs when a material forms sound waves after absorbing light. In this case, the researchers used water vapor in the air to absorb light and create sound that was transmitted directly into someone’s ear.

“This can work even in relatively dry conditions because there is almost always a little water in the air, especially around people. 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”

–Charles Wynn, lead study author

In the lab, the researchers showed that commercially available equipment could transmit sound to a person more than 2.5 meters away at 60 decibels using a laser sweeping technique. The researchers believe that the system could be easily scaled up to longer distances.



Sounds interesting. (pun intended) I have to wonder what wavelengths they use to make it safe for eyes. I won’t even look directly at a low power diode laser for fear it will cause blindness. I read about leading edge research frequently, but never hear anything more. Sometimes, it is because it was pure research and no commercial application was even envisioned. Sometimes, it takes years for something to go from university lab to production. I will be on the lookout for more on this. It has implications for more than hearing loss.