Q: iPhone 6, hearing problem

Hi Aziz, 

I understand that you are having a hard time hearing people when making phone calls on your iPhone. Let's see if we can get that sorted out.

At anytime you have issues with hearing from the receiver on your iPhone, refer to the article below. It will walk you through checking settings, cleaning the receiver as well as restarting and updating your iPhone. If you still are having issues with it, you will want to contact Apple Support. 

If you can't hear a person on a call or voicemail or if the sound quality is poor on iPhone
https://support.apple.com/en-us/HT203800

Have a good day.