look up any word, like fellated:
 
1.
The sound emitted by the world-famous, action star Arnold Schwarzenegger either in times of stress, or great pain and anguish.
"Go, get to duh choppa--Nyaaa!"
by Thomas Morris April 29, 2003
 
2.
A phrase that was oft employed by those famous lead singers of the "hair metal" genre of bands from the 1980s.
"ROCK you like a hurricane! NYAAAAAHHHHH!"
by Markus Brodigan October 26, 2003