sound decoder for bachmann model, Plux 22 version, no speaker is supplied with this decoder Below is a list of the Function keys and their assignments applicable to this model. F0. Lights on/off F1. Sound on/off F2. Double Horn Hi-Lo F3. Double Horn Lo-Hi F4. Single Horn Lo F5. Buffer up F6. Coupling up F7. Flange squeal F8. Wheel Sleeper Groan F9. Brake Release F10. Fan F11. Spyrex Valve F12. Guards Whistle F13. Shunting mode F14. Acceleration/Brake Time F15. Aux 1 F16. Aux 2 F17. Aux 3 F18. Aux 4 F19. Aux 5 F20. Aux 6 F21 Drive Hold F22. Volume Control F23. Fade Out sound