Phone backgrounds
The phrase “phone backgrounds” does not identify a webcam audio issue. Clarify what it means and what speech-capture problem you need to solve.
There is not enough information to make a supported recommendation about phone backgrounds and webcam microphone audio. The query does not establish what “backgrounds” means or how it relates to capturing speech.
Clarify the speech-capture question
Specify whether you mean a phone wallpaper, a video-call background or background sound. If your concern is webcam audio, also identify the phone or webcam, the recording or conferencing app, and the problem you want to resolve.
No device documentation, compatibility details or audio observations were supplied. Without that evidence, it is not possible to determine whether a background setting affects microphone selection, speech clarity or recording behavior in your setup.