This NY Times article describes research by Dr Wenyuan Xu and colleages at the University of Michigan into how to maliciously control a phone's accelerometer using sound waves.
In their paper, the researchers describe how they added fake steps to a Fitbit fitness monitor and played a "malicious" music file from the speaker of a smartphone to control the phone’s accelerometer. That allowed them to interfere with software that relies on the smartphone, like an app used to pilot a radio-controlled toy car.
The video below explains their research.
The image is taken from their paper.