I've listened to that track multiple times now through my SVS MTS-01's, Sennheiser HD280 Pro's and Etymotic MC5's. I don't really hear it well in either set of headphones (which surprised me) but I can hear it with the SVS's when I crank them up a bit. I'm not sure what that sound is for sure but my three guess's are (I get three right?
): Brushes on a snare drum or a wire type scraper on some sort of guiro (both of which channels could have been mixed out but still picked up on another instruments microphone if they were recorded all together) or a recording artifact. Something just creating distortion. But hey I'm really tired and my mind is not clear but I said I would get to it today. I might listen again tomorrow when i have a clear head, but no promises.
You know though, I don't always hear what that CD is trying to tell me is there to the degree they say it is. So, I don't know if that's the audiophile in them, my insufficient equipment or my tin ear.