Can't hear or be heard during calls

[AC Question]

I don't know what I accidentally pushed but when I make a phone call, I can't hear, the person I'm calling can't hear me, and then the phone automatically ends the call.

 

[B. Diddy]

Welcome to Android Central! Which phone? Are you saying that you were adjusting some settings, or did this just happen out of the blue? What happens if you change to speakerphone, or used wired or Bluetooth headsets?