"The point of including them here is that these sounds add immensely to the effectiveness of a micro or small layout. If you haven't yet tried them out, you might want to do so. To demonstrate the point, we have a newly-updated version of Ken Olsen's switching operations on his layout, Dawson Station, which was voted among this site's top favorite layouts of 2009.
"Ken's N-scale 1x4ft (30x120cm) micro layout faithfully models the Hull-Oaks Sawmill in Oregon, which was one of the last railroad-served steam sawmills in the U.S. Ken has reproduced a typical switch-run to this mill and made a video on his tiny layout to show how it worked. I'd suggest you start by turning off the sound on your computer, and watch a couple minutes of this excellent tape. Then stop, rewind, turn the sound on, and watch it all the way through. YOU'LL BE AMAZED AT THE DIFFERENCE TRAIN SOUND MAKES. Even on very small layouts!"
Just in case you want to try what he mentions: