I am super sensitive to noises, and I noticed weird noise (rattling / crackling) during scrolling, but also during high network traffic (for example when i did a network test on speedtest.net).
First I thought it was fan noise, later SSD, but finally found the cause: the built in speakers!
For now i disconnected them -> noise gone.
So if you have the same issue, you can consider disconnecting the internal speakers.
Quite probably this is caused by RFI / EMI
