Intel MBPs are notorious for this longstanding issue. You can get multiple hardware swaps from Apple and will probably find no improvement. My layman understan

Intel MBPs are notorious for this longstanding issue. You can get multiple hardware swaps from Apple and will probably find no improvement. My layman understanding is that it stems from an issue in voltage management, both on the power rail itself and on the software side. Certain types of CPU load trigger heavy crackling and popping in the speakers. Having the iOS simulator open makes it particularly egregious in my case. Add to this that the two prong power bricks mean the chassis grounds through your hands in (worse in low humidity), and in the right building it's a lot of worrying symptoms all at once.