Researchers are trying to capture speech with a motion sensor on smartphones

Researchers from 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.

The researchers from Texas A&M University, the New Jersey Institute of Technology, Temple University in Philadelphia, the University of Dayton and Rutgers University in New Jersey call the eavesdropping technique EarSpy. By internally absorbing the vibrations of the speaker 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 that person is saying.

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

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

EarSpy: Say zero six times in a row