Chosen Solution
I will be on a phone call with someone and every time I would speak or if the microphone picks up any sound, the audio would fade. They can still hear me fine. This happens even when I switch from the earpiece, speaker, or a headset. I have restarted the phone in the past and it’ll work for awhile but the problem will return eventually.
This seems to me like it’s a software issue. Make sure your on the latest iOS, if you are try doing a full reset via iTunes. If the problem still occurs contact Apple customer care. I believe you phone is still under warranty.
