I have the same issue. Here's my info: Have owned 2010, 2013, and 2017 Macbook Pro 15" models, as well as 21.5" and 27" iMacs from 2011-2015. I upgraded to a 2020-model 16" Macbook Pro in September 2021 (brand new from Apple, few weeks before the latest line was announced). Upon using the new 16" out of the box, I started noticing this audio pop/crackle issue almost right away. Mostly when multitasking & switching windows while having music or video streaming from Spotify/Firefox. Apple did a repair on the laptop to replace the speakers, but the issue wasn't fixed. Spending more time on the phone with a senior advisor now, he's gathering logs to submit to engineering to review.