I'm pretty sure those fans were added when the P motors were rebuilt for the Hudson division. I never saw one on the Harlem. There was fairly dense housing in nice areas within 100 feet of the tracks, and that noise would have generated a political firestorm. Their power wasn't needed on the Harlem where 10 cars was a long train. Between GCT and Harmon you could often see an 18 car train.
I was tempted to suggest that they might sound like a GG-1 but for the fact that the gearing must have been very different. The "Electric Zone" through CUT had a 60 mph speed limit. The GG-1's were capable of over 100. One of my NYC colleagues rode a GG-1 from Philadelphia to New York on a Florida train that was running late and saw the speedometer get up to 112.
The CUT motors might have sounded like New Haven's similar EP-3, but in those days any railfans doing sound recording were chasing steam. I'd think it a minor miracle if there exists a recording of main line electrics in the U.S.
