I’m in Shannon. When I transmit, I also hear myself in my ears from a receiver co-located with my transmitter (or sometimes from a different receiver for the first second or so, when the black box of the Best Site Selection system we have thinks that’s what I want to hear, for some unexplained reason).
When I have a phone line open, I get radio in one ear and phone in the other. If the controller I’m speaking to on the phone is transmitting on their radios, I hear their transmission but usually not the response from the aircraft (occasionally I hear it weakly in the background, but I suspect that’s just that they have their earphones turned up very loud or they have radio on their speakers as well – it’s never been loud or clear enough to think it’s being relayed from the radio into the phone line). That’s certainly true for when I talk to other controllers in my unit or Dublin, London, or Scottish