Traction motor sound disabled RPM rate 1 (Highest) RPM rate 2 RPM rate 3 RPM rate 4 RPM rate 5 RPM rate 6 RPM rate 7 RPM rate 8 RPM rate 9 RPM rate 10 RPM rate 11 RPM rate 12 RPM rate 13 RPM rate 14 RPM rate 15 (Lowest)