Research demonstrates how vibration motors in wearables can be used to "listen" to speech

6/6/2016 Julia Sullivan, ECE ILLINOIS

In their paper, ECE and CS Associate Professor Romit Roy Choudhury and ECE PhD Candidate Nirupam Roy explore how the small vibra-motors common in most smartphones and wearables can be exploited as a listening sensor, similar to a microphone, without requiring machine learning or pattern recognition to extract words and phrases.

Written by Julia Sullivan, ECE ILLINOIS

Associate Professor of Electrical and Computer Engineering and Computer Science Romit Roy Choudhury and ECE PhD Candidate Nirupam Roy knew that vibrating objects generally respond to air vibrations, so it stood to reason that the vibration motor in a smartphone could act as a microphone. They made an unexpected discovery when they came to understand that the output of these vibra-motors needed only basic signal processing to recognize the words and phrases. The two have published their findings in a paper, Listening through a Vibration Motor.

The implications of their research present new opportunities and threats. "Even modest reproduction could prompt new applications and threats. On one hand, wearable devices like fitbits, that otherwise do not have a microphone, could now respond to voice commands…On the other hand, leaking sound through vibra-motors opens new side channels - a malware that has default access to a phone's vibra-motor may now be able to eavesdrop into every phone conversation," wrote Roy and Roy Choudhury.

Their research has already gained media attention, including TechCrunch, Tech Times, Android Headlines, Softpedia News, Engadget, Tech Worm, Tech.Mic, Chicago Inno, and Chicago Tribune. Congratulate them on their publication by leaving a comment in the ECE Illinois LinkedIn group for alumni and friends. 

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This story was published June 6, 2016.