Missed this: turns out Tom Owen, the expert cited to prove that it was not Zimmerman who screamed, also thinks that GZ said “punks”:

articles.cnn.com

Forensic audio expert Tom Owen, who analyzed 911 recordings, agreed the garbled word that raised controversy was “punks,” not the racial slur some people said they heard.

When Owen, chairman emeritus of the American Board of Recorded Evidence, used a computer application to remove cell phone interference, the word became clearer, he said. After discussions with linguists, he said he became convinced that Zimmerman said “punks.”

He provided CNN with a copy of the newly processed audio.

CNN also enhanced the sound of the 911 call, and several members of CNN’s editorial staff repeatedly reviewed the tape but could reach no consensus on whether Zimmerman used a slur.

So every guy with audio enhancement software hears his own thing. “Coons”, “cold”, now “punks”. That’s why I thought the claims of enhancement were dubious from the start and had more to do with fetishization of computers, forgetting about the “garbage in, garbage out” principle. Also, yes, turns out those innocuous filters cleaning up noise do change things enough to change the interpretation of a whole word.