Thanks, I got those now although they were both already set to 'off'. I've done a few tests now and there's definitely something really off with my sound. Not that I'd wish problems on you guys but I'm hoping I'm not the only one and I'm hoping there's a way to fix it.

If I'm on a tournament and put my psp into sleep mode then start it up again, every race in that tournament will have no ambient sounds at all as far as I can tell. Completely gone. However, starting from the main menu (for example the first race of a tournament or a single race), I'll have sounds. But, strangely, not always all of them. For example, starting a sinle race on Fort Gale, I had no crowd sounds at all. But I did have rain, thunder and the noise of that round tunnel during the opening sequence. When the ships start up, however, the levels are so low on the ambient sounds that they're very hard to hear.

Doing a complete restart of the system and selecting Fort Gale again, I had crowd sounds back but the sound of that tunnel was completely gone. Overall the ambient sounds seemed louder. Playing a few more races (without going into sleep) my PSP seemed to drop more and more sounds until I was back to silence.

When you turn the music off, the voice vanishes from the race intros so it's easy to hear what's missing and what's not.

It's a shame because someone must have put a lot of work into the sounds and I used to love racing Pure with no music to hear the sounds.