iPhone 6 can't hear anything while calling (speakers are working)

Hey, I have a problem with my iPhone 6. I can't hear any receiving calls, the caller can hear me perfectly fine. It doesn't work with any of the speakers (they are both working), headphone jack or bluetooth. Even I tried to call from the Macbook using the FaceTime option to call from the phone. The sound just not come out of the phone in any matter while calling, everything is fine if the call is over internet (FaceTime, Skype, Viber)