Is this because we deal with little old deaf people? A little. But the main reason is because we are frequently consulted to wake the dead (or at least try) and evaluate the comatose. In order to do so you need to make sure that this person definitely isn't responding. So you learn to be able to shout into their ears in the gigadecibel range, to see if they can actually hear you.
And you yell simple commands, trying to break through a wall of brain damage, drugs, and loud ICU machines to see if there's anyone in there. "MR. JONES! CAN YOU WIGGLE YOUR TOES FOR ME?" or "MRS. SMITH! CAN YOU SHOW ME TWO FINGERS?"
If you don't believe me, just ask any ICU nurse. They often carry their own earplugs for when they see a neurologist going into a patient's room.
So this morning I got called in to evaluate a guy with brain damage named Mr. Dick.
So I did my usual shouting routine to try to wake him.
"MR. DICK! CAN YOU HEAR ME? CAN YOU HOLD UP TWO FINGERS?"
"MR. TOES! CAN YOU WIGGLE YOUR DICK FOR ME?"
Mercifully, the patient didn't respond. The nurses' station, however, broke down in hysterical laughing. So did the patient 2 doors down. I'm sure I turned bright red when I realized what I'd said.
Leave me alone. It's 5:00 a.m., and I haven't had a Diet Coke yet.