A few days ago when watching videos on my Dell laptop, they started to intermittently produce a short (less than 1/2 a second), sometimes loud, buzz which also stuttered the replay of the video. I read posts about power or fan/dust or CPU/cores issues. What it turned out to be was software installed automatically by Dell earlier in the week, I assume after I had applied some Windows updates. The fix was to uninstall Dell Support Assist and Dell Support Assist Agent.
The software is made by a third party (PC-Doctor) so it is possible the same issue may arise on other systems.