Question: iPhone 7 / Plus microphone issue (FIX)
If you call someone and they said that they can't here you clearly, or the call sounds muffle then this "fix" is for you.
Guys, listen! The problem came from the back microphone (the noise cancellation one, between the flash and the camera) You can test it by yourself, just call somebody and cover with your finger the back mic and you will see not a great but significantly better results. I covered mine with a duck tape since I find out about this problem, the person who I call, from the other side said that he can hear me a lot crisper then before.
So what you gonna do is to take a little peace of a duck tape and stick it on the back microphone. Try it out, for now this is the only trick or fix or what ever you call it that can make your calls better. It might be a software issue with the iPhone 7 and 7 Plus series internals, or some crappy mics going on, who knows, even Apple has no idea what cause the problem - but anyway you can try this by your own and see if there is some changes.
iPhone 7 Plus, iOS 11.2.6