Researchers have found that accelerometers, the motion-sensing chips used in smartphones, tablets, and other digital devices, as well as automobiles and medical equipment, can be hacked using sound waves, The New York Times reports. In a new study, computer security scientists from the University of Michigan and University of South Carolina demonstrated that accelerometers could be manipulated using a “‘malicious’ music file.” They were able to add steps to a FitBit counter and control a toy car, exposing the possibility for much more dangerous meddling in devices as varied as self-driving cars and pacemakers.

One of the authors of the study, Kevin Fu, a University of Michigan associate professor of electrical engineering and computer science, told the Times, “It’s like the opera singer who hits the note to break a wine glass, only in our case, we can spell out words. You can think of it as a musical virus.”

The researchers tested 20 accelerometer chips from five different manufacturers, and found that they were able to hack 75% of the chips, according to the Times.

Find a more in-depth explanation of the hack below.