Audio broken by kernel update

[Evgeny Kapun <abacabadabacaba@gmail.com>]

After I upgraded my system, my integrated sound card (Intel HDA) stopped 
working properly. The sound plays, but it is severely distorted.

If I boot the same system with an older kernel, it works. Currently, I 
am using kernel 6.6.13+bpo-amd64, because newer versions that I tried 
don't work (in particular, 6.8.11-amd64 doesn't work).

What can I do to fix it (without having to run an outdated kernel), or 
to investigate it further?