What's the deal with single sound file whistles and horns

[Railfan587]

How do you make single sound file whistles and horns? The Black 5 and the Just Trains A4 Pacific has a single sound files whistles. My question is how are they looped ?

[simer4]

Using Wavosour, open up your .wav file. Highlight the area you want looped, flip down Tools -> Loop -> Create Loop Points. Save the file, and there you go.