My microphone on my 7 plus just suddenly stopped working. I factory reset it and it started back working but only for an hour or 2 then it stopped again.
I don’t know if it is a software problem or if the mic itself is damaged.
iPhone 7 Plus
Hello,
Try the steps in this article:
If the microphones on your iPhone, iPad, and iPod touch aren't working - Apple Support
The exact thing happened to me, after the update my 7 plus mic stopped working. I called Apple and I was told to reset to factory settings and it worked for about an hour and then it stopped working again.
iPhone 7 Plus mic not working
