Yes, there are many components to train noise. I used to live by rails with a small incline, and the diesel locomotives made a loud low noise accelerating uphi

Yes, there are many components to train noise. I used to live by rails with a small incline, and the diesel locomotives made a loud low noise accelerating uphill from a station, while downhill the trains moved far faster and the engines were quite insignificant compared to noises due to speed: mainly the wheel noise and going over the expansion joints.