Gesture Control System Uses Sound Alone

Uses Sound Alone
SoundWave lets an ordinary laptop function like a Kinect sensor.
MONDAY, MAY 7, 2012BY RACHEL METZ

When you learned about the Doppler Effect in high school physics class—the wave frequency shift that occurs when the source of the wave is moving, easily illustrated by a passing ambulance—you probably didn't envision it helping control your computer one day.

But that's exactly what a group of researchers are doing at Microsoft Research, the software giant's Redmond, Washington-based lab. Gesture control is becoming increasingly common and is even built into some TVs. While other motion-sensing technologies such as Microsoft's own Kinect device use cameras to sense and interpret movement and gestures, SoundWave does this using only sound—thanks to the Doppler Effect, some clever software, and the built-in speakers and microphone on a laptop.

Desney Tan, a Microsoft Research principal researcher and member of the SoundWave team, says the technology can already be used to sense a number of simple gestures, and with smart phones and laptops starting to include multiple speakers and microphones, the technology could become even more sensitive. SoundWave—a collaboration between Microsoft Research and the University of Washington—will be presented this week in a paper at the 2012 ACM SIGCHI Conference on Human Factors in Computing in Austin, Texas.

The idea for SoundWave emerged last summer, when Desney and others were working on a project that involved the use of ultrasonic transducers to create haptic effects, and one researcher noticed a sound wave changing in a surprising way as he moved his body around. The transducers were emitting an ultrasonic sound wave that was bouncing off researchers' bodies, and their movements changed the tone of the sound that was picked up, and the sound wave they viewed on the back end.

http://www.technologyreview.com/web/40368/?p1=MstRcnt
It's amusing that they use a mac in the image example...