There were many variations of the Williams Train master. The earliest ones had no reverse, no horn and plastic side frames and handrail stantions. Later the handrails went all metal. Then the buzzer horn just like postwar models.
If your box does not mention horn or Truesounds then chances are good that you don't have any sounds. But thanks to today's technology, you can add it if you like.
LOTS of variations is correct......
Williams even sold kits were people could provide motors and trucks.
I have a SD-45 w/o horn or bell....just a DCRU.
Open the FM and see,,,,it's very easy.