playing sound

How to get sound working in game engine ? activate with keyboard would be enough. i can t get the sound working.

open a game/demo with sound ( there’s some here in the site) and play it.
Is it sound working?
If yes, it’s quite simple to put sound in your demos!
Load an WAV sample with Panels -> Scene -> Sound panel ( blender sound block button) and then use it the way you want, ex (Logic Bricks):
Collision Sensor -Prop: wall> AND -> Sound Actuator- “loaded.WAV”
this setup will play the “loaded.WAV” sound when the object with these Logic Bricks collide with an object with property “wall” assigned.
Is this clear?