https://consumerist.com/2017/09/27/apple-promises-to-fix-weird-crackling-noise-on-iphone-8-and-8-plus/

A new smartphone fresh out of the box shouldn’t make crackling noises during your phone calls, but that’s what users of the new iPhone 8 and 8 Plus report, and they’re customers of different mobile carriers. Apple has acknowledged the problem, and promises that a fix for it is on the way.

One of the users experiencing the static-like problem is an editor at The Verge, which might have helped to make the problem more visible. However, users in all of the places where people typically discuss Apple device problems — Apple’s support forums, Macrumors, and Reddit — have showed up to discuss the issue.