I found this today but it's got me thinking that I may go on another time-consuming search.
It's the 'scream' that's heard in the Grandmixer DST track, Why Is It Fresh? at the part where the guy says, "now why don't we make believe we're in school....".
I found the scream whilst listening to a Power Records rip on Youtube. It's all rather silly with some over-the-top voice actors and the scream appears behind some speech. The fact that it's not entirely clear makes me wonder that it was a stock piece of audio and must've been taken from a larger library of sounds.
I fear I shall not rest until I've found the proper source.....
This goes out to my boy, Irish Craig in particular.
Go to 4 mins 35 for the scream.
The scream is here at 4mins 27 of this Captain America adventure.