Adding to my previous comment, here is a good video which you can clearly audibly hear the different motor phrases as the train gains speed. Listen in particular from 01:55 onwards. As the train speeds up, you can hear the motor go through a different phase, heard at 02:13. This is what we are missing in TSW from the 377. As we only have that very basic acceleration sound, regardless of the speed and/or power applied. I believe it is something to do with the Gate turn-off thyristor (GTO) although don't ask me what that is or means I hope more variations in motor sounds have been added to the 375, as it would certainly make it a lot more fun and interesting to drive.