wierd echo on the sounds

Every time i play the map i am making, there is some wierd echo on all the sounds and music, and backround noise. It is only on this particular map, all my other maps are fine, so it is not the soundcard, methinks. Does anyone know what might cause this?

Its probably because you have set ambient sounds to psychotic (too lazy to dl).
psychotic echos all sounds. its cool for a while in the right map, but it gets annoying after a time. id not use it.