Fifty years ago we imagined the future would be filled with flying cars, robot assistants and video phone calls — The Jetsons, basically. We got some of that, (maybe next century, flying cars), but what those imagined realities conveniently left out were the trade-offs; specifically, cameras and microphones everywhere. Assistants like Alexa come equipped with microphones, always listening for its wake word. Phones, computers and everything in between ship equipped with countless cameras, so you can see the person on the other end of the line.

Our future came at the expense of privacy and the onus is on consumers to protect it from prying eyes and ears. This has given rise to simple solutions like the camera cover — put something over the lens and you can be sure no one is secretly peering at you through your camera. How about microphones? How can you ensure no one is secretly listening in and, if they are, how can you block them? What’s the microphone equivalent of a camera cover?

Via Allison Burtch

The answer is a mic jammer: a device you can put near a microphone-equipped gadget that fills its ears with noise. “I’ve always been interested in creating hardware solutions to software problems,” says Allison Burtch, founder of IRL Research Lab. Burtch created an open-source mic jammer back in 2014 as part of a thesis project. “Software solutions are subject to hacking and users don’t actually know what’s happening behind the scenes. I wondered if there was a way to turn off your smartphone’s microphone in a way where you could still use the phone, but also guarantee that your mic was off.”

The camera cover is genius in its simplicity. Forget what the indicator light says or whatever hacker has made a home in your system, the camera can’t do camera things simply because you’ve cut off the camera’s ability to see by using physics. Snoopers can’t beat science.

A mic jammer offers something similar — using science, not software — to prevent a device from listening in. “Back at NYU, my professor Eric Rosenthal and I devised a circuit that emitted a noise just above the range of human hearing, but square within the range of the iPhone’s microphone,” says Burtch. The result: a block on Siri’s hearing.

Burtch offers up the schematics of her mic jammer on her GitHub. Since Burtch’s work in 2014, we’ve seen other jammers emerge. One team at the University of Chicago developed a “bracelet of silence” in 2020 to combat always-listening mics. That same year, the art collective brought a mic jammer to consumers with its Alexagate product. More recently, in April of 2022, engineers at Columbia devised an algorithm that plays “whisper-quiet sounds” in order to cancel out 80% of communication a smart speaker might pick up on. The algorithm only works with English at the moment but the team hopes to introduce support for other languages eventually.

And that’s just to confuse microphones. Elsewhere, others are using clothing and makeup to outsmart facial recognition technology.

Microphones feel omnipresent now more than ever. While mic jammers may not be as ubiquitous as their webcam cover cousins, it can be cathartic knowing the technology exists, should a company want to ever implement it. And rest assured, says Burtch, “the high-pitched sound won’t drive your pets crazy.”

Written By: Xavier Harding

Art By: Shannon Zepeda