IPHONE 6, 7,8 MIC ISSUES_OIS11

I bought my iPhone 8 Plus little over 1.5 months ago. I gave my wife my mint condition iPhone 6 . My daughter has an iPhone 7.

All devices are running IOS11.2 . The microphone on my 8 is useless . The amount of call backs I have to make to just get a conversation finished is ridiculous . The same applies to the iPhone 6 that I gave my wife . Since upgrading to IOS11 she now has the same problem along with a bunch of others since the upgrading to IOS 11.

Apple has a serious issue to resolve . These devices are called IPHONE . Means its a telephone amongst other things .

Strangely enough I am not finding one complaint of a mic issue on the iPhone X. Coincidence?

Anyone who can share fixes or their most recent stories of problems ....please share .

Thanks