Yeah but... those are DC machines, so the only real sound is gear noise and the occasional clacking of the control contactors, much like a diesel as it makes transition. The GN Y-1s were AC machines with a big motor-generator set to supply DC to the traction motors. I would suspect it made a continuous monotonous drone, similar to traction motor blowers, but exactly what it sounded like is anybody's guess.

Dennis Storzek