I heard it the famous word "Oh Shit" echoing.

After an half an hour or so her head popped up over the edge red faced not because of the climb but because she didn't expect to see me.  There was a shuddering stammer in her voice. "Sorry" she said.

I have heard the "OH SHIT" word more often than the word "FALLING."
Even once in a while "NO SHIT, DAMN or OH."  Or even if you hear an off sounding sound BREAK!  Even thought the proper word is "FALLING." I guess it depends on who you are climbing with.

My experiences being around different groups they seem to have their own language, but did notice that when one went with another group he/she was able to communicate with them in their language. 

What is important is that the belayer listens for a sound that is not normal and react to that sound that, that person is going to fall or is falling no matter what.  It is better to react now than later when the rope has slid through your hand a few feet then try and stop the fall. 

This is the advice I gave to all my students
Remember the belay is no better than the belayer!

In other words your the faller is just a rope length from eternity.
It takes 3.5 seconds to fall 200 feet.
150 pound peson falls 20 feet and is stopped in the next 20 feet he will weigh 300 pounds.  Deceleration is 1g. Now if he is brought to rest in 2 feet after the 20 foot fall he will weight 1650 pounds.  This deceleration is equal to 10g's.

From Seirra Club, Belaying the Leader 1965 Pg. 35.
From Sierra's Belaying the Leader.
From Royal Robbins Basic and Advanced Rockcraft.
1971 and 1973.