Security researchers warn it's possible to eavesdrop on you using the the sensors in your smartphone. They aren't talking about the phone's microphone but about its gyroscopes, the sensors that are used to measure the phone's orientation and enable motion-based games. The security risk lies in the fact that smartphones automatically give apps and websites access to these sensors because they're seen as safe.
For now, the researchers’ gyroscope snooping trick is more clever than it is practical. It works just well enough to pick up a fraction of the words spoken near a phone. When the researchers tested their gyroscope snooping trick’s ability to pick up the numbers one through ten and the syllable “oh”—a simulation of what might be necessary to steal a credit card number, for instance—it could identify as many as 65 percent of digits spoken in the same room as the device by a single speaker. It could also identify the speaker’s gender with as much as 84 percent certainty. Or it could distinguish between five different speakers in a room with up to 65 percent certainty.
But Boneh argues that more work on speech recognition algorithms could refine the technique into a far more real eavesdropping threat. And he says that a demonstration of even a small amount of audio pickup through the phones’ gyroscopes should serve as a warning to Google to change how easily rogue Android apps could exploit the sensors’ audio sensitivity.