Describe the Suggestion

I understand the mod name is Steam 'n' Rails, however, with the new narrow and wide tracks, it would be a nice feature to add Electric and Diesel train noises to the mod. Because you can already change the icon that shows up in the station, it could connect well with the different types (Electric Multiple Unit, Electric Loco, Diesel (MU, Loco), Steam) of trains that can be built; plus, I think it'd add a bit more realism to underground subway systems.

For the electric, it could range from anything as simple as a single sound hum with wind and axle noise, to something a bit more elaborate like a GTO-VVVF inverter sound.

Diesels I don't have much experience with, but I'd assume it's something similar to just speeding up or slowing down a few sounds that blend between each other.

It's more aesthetic than functional, but I feel like it'd improve the realism and feel of the trains.

Screenshots and Videos

Example 1: DB 481, EMU
https://www.youtube.com/watch?v=GwZfSEsDXSA

Example 2: Keikyu N1000, EMU
https://www.youtube.com/watch?v=YF9P-F-jd7A

Additional Context

After looking at some of the induction-recorded audio graphs, I came to the conclusion that these are very tight square waves with a sine wave mixed in. I don't know how well, if at all, Minecraft can handle sound generation, or if those noises would have to be made beforehand, but if it can at least pitch-shift a playing sound, should be good. There of course would need to be some work on the processing, since just combining two sounds will make it sound really harsh (some rounding, softening, limiting). Alternatively, some of the trains have just two sounds (acceleration and deceleration, cruising) that seem to pitch-shift.

By the way, glorious work on the bogeys, monorail and conductors, really sweet stuff!

Bonus points if you can make it sound like the cries of the damned (AKA The BART) https://youtu.be/QrjMkm8GOWg?si=zzOcnHVQewBo3zow