If you’ve studied audio technology at all then you know that loudspeakers/headphones and microphones are both principally the same in how they operate, they just work backwards from one other. Where the diaphragm of a microphone responds to moving air molecules to turn sound into an electronic signal, the loudspeaker turns an electronic signal into moving air molecules thanks to the motion of its diaphragm. We’ve used loudspeakers as mics in the past, most recently with the popular subkick on kick and bass, but now an Israeli company has found a way to turn headphones and earbuds into secret microphones to record the surrounding conversations.
Researchers at Israel’s Ben Gurion University have created a proof-of-concept exploit called “Speake(a)r,” that found that headphones were nearly as good as a microphone at picking up audio in a room. The hack is done by restasking the RealTek audio codec chip output found in many desktop computers from an audio output to an input. Apparently this is fairly easy to do, but hackers just haven’t it discovered it yet. The worst part is that it doesn’t even require a new driver, since the embedded chip has no security built into it and is easily reprogrammed.
Keep in mind that this is just a proof-of-concept, so no need to worry about your conversations or your audio tracks being compromise yet, but it does bring up a big question about the security of the everyday computer peripherals that we all use. Probably the last thing we ever think about is the cyber-security of our audio gear, but perhaps its time to be concerned.
What’s worse is the fact that audio professionals usually use higher-quality headphones than the average earbud listener, which means that the capture quality is better as well, although I’m not exactly sure the frequency response would be that good with closed-back headphones tightly fitted to the head. Then again, it’s pretty rare that matters of national security is discussed in a recording studio (unless you’re with Jeff “Skunk” Baxter). Still, it’s time to be aware that some of our everyday studio gear can be turned into secret microphones.