Peer up close at the glass surrounding your smartphone’s display and you’ll notice a few extra components tucked in up there: those include your front-facing camera, maybe a front-facing flash if you’re lucky, and also a couple nondescript little dark circles. Plenty of us don’t give those a second thought, but those circles make up the proximity sensor on our phones, letting the handset detect when we’re holding it to our face, making a call (and preventing our cheeks from doing all sorts of touch-screen mischief in the process). While the prox sensor plays a useful role, phone makers are always interested in simplifying designs and reducing component count, and now one company thinks it has a way to retain prox sensor functionality while doing away with that extra hardware altogether.
The system cooked up by Elliptic Labs uses your phone’s existing earpiece and microphone to emit and detect high-frequency sound waves that are outside our normal range of hearing. When we raise a handset to our face, the presence of our head would block some of those waves and allow the Elliptic Labs software to effectively act as a prox sensor.
In theory, that sounds like a pretty graceful solution, but we’re not quite sold just yet. After, that kind of detection sounds like it requires some pretty constant audio analysis, possibly hurting power consumption. And while it would certainly allow manufacturers to ditch dedicated prox sensor hardware, we’re talking about a tiny, tiny component to begin with. Do the benefits outweight the costs? Well, we don’t know just yet, but Elliptic’s reportedly got a few OEMs looking into putting its system in some future phones, so we may get that answer soon.