I have never had this audio issue on my older mac computers. Now this is a big problem on my brand new iMAC with BigSur. I am currently updating to ver. 11.4 but it doesn't seem to solve the problem based on the comment above.
The "sudo killall -9 coreaudiod" command does NOT work for me.
This issue is extremely frustrating... Hope Apple fixes this bug ASAP. Or if anyone has some solution to audio clipping/popping issue on BigSur OS, please help.