It sounds more like when the chip is powered the buzzing stops.
This is a fairly common thing with cheaper hardware. For example, many cheap tablets have the exact same thing - a buzzing sound from the speaker(s) unless power is applied to the audio chip, normally due to internal interference.
I've had the same thing with unshielded desktop Harmon Kardon speakers (production year ~1998 or so) which buzzed when there was any electrical interference nearby (e.g. a wifi signal). That's not fixable in software.
You should be able to disable power saving on the chip and keep it active to work around the issue (e.g. check
/etc/default/tlp and disable all audio-related power saving); it's not a real solution though.