The complete numbness and paralysis caused upon sudden realisation that you still have your speaker volume turned up loudly.
This realisation usually comes when the following occurs:
a) The windows shutdown theme plays
b) You roll over a movie trailer advert
c) You decide to watch some porn
When Speaker Shock is engaged, the victim feels the need to blindly press ANYTHING, be it connected to the computer or not, in order to get it to stop.
Oh man, I got total Speaker Shock after playing Team Fortress last night, when I decided to toss the salad. My mom was in the next room!