Researchers are trying to capture speech with motion sensors on smartphones

Researchers at several American universities have tried to eavesdrop on smartphone users by capturing data from motion sensors in the smartphone. The method appears to be of limited use.

Researchers at Texas A&M University, New Jersey Institute of Technology, Temple University of Philadelphia, University of Dayton and Rutgers University of New Jersey call the eavesdropping technique EarSpy. By intercepting the vibrations of the speaker internally with the motion sensor, the software can, among other things, check with some reliability whether a man or a woman is talking and which numbers the person is saying.

The technology does have many limitations, because apps can read motion sensors with a maximum of 200Hz, instead of 540Hz, for example, without explicit permission from users. As a result, the speech is more difficult to catch and the speech is less recognizable.

The researchers did the tests with a OnePlus 7T on Android 11 and a OnePlus 9 on Android 12. The researchers conclude that even with the 200Hz limit, eavesdropping on conversations with motion sensors in smartphones is limited.

EarSpy: Say zero six times in a row