Buzzing sound from speakers when scrolling or mouse movement in Chrome or Firefox
Solution 1:
I have the exact same behavior on my PC right now, and I know exactly why. It is caused by interference generated by my Steinberg UR-44 USB Audio Interface. If I unplug it, the problem vanishes and resumes immediately when it is reconnected.
In fact. I found that replacing the USB cable itself made it possible to reconnect the audio interface without the noise, solving the problem.
Although this may or may not work for you, if you have external USB devices or other equipment plugged into your machine. It might be worthwhile to disconnect them and see if the sounds persist or not. If they stop, plug each item back in one at a time and see what happens.
Hopefully this might be helpful.