Cross-section of the SINTEF microphone including the readout electronics.
Can you detect sound using light?
This is Sandra Tsing Loh with the Loh Down on Science, and on a new improved microphone.
It's the brainchild of Scandinavian engineers at the research organization SINTEF. See, traditional microphones can suffer from problems like background noise, and an inability to tell exactly where sound is coming from.
This new optical microphone can make listening to conference calls less [garbled words] and more "Thanks for sharing those terrible stats, Bob!"
The keys? A laser, some sensors, and a membrane 1,000 times thinner than a human hair. The lightweight membrane waves freely in the air, so is more sensitive to a soundwave's direction. And the laser, bouncing back and forth off the membrane, can measure slight motions incredibly precisely. The laser light's intensity is measured by sensors, which translate it into an electrical signal. Then it's more like a typical microphone or speaker, with the electrical signal being recorded or broadcast.
That still doesn’t mean you can keep it on when you leave for a bathroom break! Just sayin’.
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