Phone 6S 64Gb
iOS 10.2 - upgraded yesterday
earphones - Apple original
problem - when placing a call or receiving a call can't hear the other person nor can they hear me.
Work around - press on speaker , mic and speaker start working, press again speaker and all goes back to normal.
happens all the time since upgraded!!!!!
iPhone 6s, iOS 10.0.2
I had this issue too and a simple reboot fixed it for me.
I rebooted my iPhone several times but this did not help.
During the call you can press the speaker icon twice and it will work for a while but neither that nor reboot does solves the problem permanently (at least not for me)
Did you try a hard reset? (home button + power until you see the apple logo)
Also check for any carrier update in General>informations
Audio input & output stop working after 10.2 upgrade
