We believe that MyLocoSound is now the only economical, full function, analogue DC sound system which is readily available worldwide. It is designed to be used on large scale railways and the soundcards are too large to fit in HO, OO, N, etc. small scale railways. The obvious way to implement sound on a small scale railway is to convert to DCC but that is a major expense, a lot of work and a new learning curve for many modellers.
A very simple alternative is to install a MyLocoSound soundcard under the baseboard with the speaker on top of the baseboard hidden in scenery or buildings. You can then fit buttons at your control panel to sound whistles, horns, etc. The obvious limitation is that the direction the sound is coming from will not move with the locomotive but that is often okay with small layouts and dioramas.
The wiring is simple as shown above. The 9 to 12 volt DC power supply can be from your controller or a regulated mains plug pack. The track connection is the feed from your controller to the track. The example alongside is for steam.
Soundcards for small scale analogue DC