If the sound does not start when you run the locomotive with a sound decoder installed try the follwoing:
1. Make sure you have selected the locomotive on a throttle. The sound will not run unless the locomotive is addressed in the system.
2. Make sure the sound is not muted. Try toggling F8 which is the Digitrax standard function for muting the sound decoder.
3. Made sure the volume in your decoder has not been turned down to a very low level.
4. Check your installation to make sure the decoder is installed properly.