It's my understanding, at least with PS2, that it's not just a sound file. It's a "personality" file which also contains factors that translate feedback from the tach reader into track speed, etc. These same data points also control the chuff rate on steam locos, and prime mover RPM levels on diesels.
So why does this matter? The driving wheels on a GG-1 are slightly larger than those on a typical diesel. So if you use a GG-1 sound / personality file in a diesel, the loco's actual scale speed will be about 10-15 percent slower than the commanded speed on the remote. It will also run slower than PS2 / PS3 locos with factory sound files. I *think* that you can correct this issue by using a custom tach tape with a different number of stripes / spacing, compared to the factory tape. If I'm mistaken about this, I hope someone else will step up to correct me.