electronic sensor tagged posts

Prototype technology could enable smart home systems that don’t record speech. Microphones are perhaps the most common electronic sensor in the world, with an estimated 320 million listening for our commands in the world’s smart speakers. The trouble is that they’re capable of hearing everything else, too.

But now, a team of University of Michigan researchers has developed a system that can inform a smart home — or listen for the signal that would turn on a smart speaker — without eavesdropping on audible sound.

The key to the device, called PrivacyMic, is ultrasonic sound at frequencies above the range of human hearing...