It is completely software issue. Intel macbooks start crackling after upgrading to Monterey. High Sierra/Catalina/Mojave had no issue.

Could you please post the exact steps to do in safe mode?

In my case, the issue takes place when Firefox is the source of music and some other app does an intensive CPU usage, like IDE. Another case is 2x video speed up at udemy.com in Firefox. It almost disappears at 1.5x and completely disappears at 1x. It is easily distinguishable between sound corruption and just speeded-up sound (you can compare the same on different devices). MBP 16 2021 M1 Pro Monterey 12.1

@ag-man thanks for the clarification! I thought that some additional steps had to be done after booting in safe mode. Nevertheless, the sound corruption is still there in both cases either in safe mode or normal boot. The 100% way to reproduce - 2x video speedup at udemy.com opened in Firefox. The details I've posted in a sub-thread for the next message.

Hi! Have you got installed Monterey 12.6? Does the issue still present?