Soundscapes are a combination of an audio CD, with continuously playing background sounds of specific environments or scenes, and a WAV sound CD with a wide range of individual sound effects associated with that particular subject.
This makes them ideal for themed environments and storytelling.
There is free software that allows you to download a keyboard to trigger any of the individual sound via your computer. You can also download them to iTunes and use them directly or via an iPod.
In this way you can play the background sounds and the individual sounds together whenever you want.