Audio distortion in Big Sur?

I have confirmed that it’s related to sample rate mismatches between the content and the output device.

Previous versions resampled content to match what the device was set to, but that appears to be broken in Big Sur.

As a temporarily workaround, if you hear distortion, open Audio Midi Setup and select your current output device. Then pick each sample rate from the list until the problem goes away.

Most content and devices seem to match at 48kHz, but for some (like ripped CD audio) you will need 44.1kHz.

Yes, only online in Safari. Not in Firefox. Chat support had me try a different user; try safe mode, and resert NVRAM and PRAM. Nothing succesful other than using Firefox

No problem of any sort on my mid-2015 15” MBP which suggests to me 3rd party apps may be a cause.

Same problem here, but not just with system sounds. Some sounds in Safari are distorted. Sound being piped through Audio Hijack becomes distorted after a short time, Google Meet and Google Hangout calls are only usable in Chrome (unintelligible on Safari)

Some have suggested playing with sample rates in Audio Midi Setup to see if you can find a rate that works better for each individual output device, but this hasn't been of much help for me.

I imported MP3 audio files (320 kbps) into iTunes Music and they play with horrible distortion, breaking up and horrible sound quality in general on my MacBook Pro. Some of the files were there imported before the update when I was running Catalina with no problem and these also distort and crackle now as well. With every update they seen to find a way to break something new. On Catalina imported albums would randomally separate into two sections and I had to manually restore them into one album. Since the sound quality effects everyone's user experience, one would think this would have been noticed and fixed before it was released. iTunes Music just gets worse with every new operating system!