I got this sample from a track in 2000.07.15 - Sander Kleinenberg - Amsterdamse Bos, New Frontier - Netherlands, Amsterdam. It is a progressive house track with a female vocal, she's just making high pitched sounds (the only way that comes to mind of describing it).

The sample goes for 14 seconds - I've cut the sample so it will play in loop mode without skipping beats. I've got this on CD somewhere as well, not sure where though.