I bought one with sound but I wonder if there is any adjustment for the sound level?
I believe after the black switch is on you can push the white button for mute, level 1; 2; and 3 for each press of the white button. You need a skewer or toothpick to get to the white button.
Scaletrains should have instructions but they don't.
See if that works for you.
Good Luck, Ed