there is space for a speaker provided in the fuel tank, replace stock motor decoder with a sound decoder via 8 pin socket, brand choice is up to you, soundtraxx and QSI, both have a DDA40X sound sets for their decoders, for other brands, use a GP/SD40 sound decoder.
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x018.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x022.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x025.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x021.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x024.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x018.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x022.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x025.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x021.jpg)
![](http://i46.photobucket.com/albums/f123/river_eagle/HO-Scale/dda40x024.jpg)