are you saying that a cellphone accelerometer can be used as a microphone? That sounds… interesting. Do you have a source?

I’m skeptical too, it sounds very hard to do with the sound alone, but lets assume that part works.

The keylogger part could be done with a malicious website that activates the microphone and asks the user to input whatever. The site would know what you typed and how it sounded. Then that information could be used against you even when you are not in the malicious website.