The Sounds of Surfboy

[chems1919]

Does anyone know what instrument or object is making the noise that starts at about 3:12 in Surfboy? It sounds like a horn or something, but it's unlike anything I've heard. I know it sounds weird, but I think that was the moment when I realized how epic Underworld is...I was listening to dubno for the first time many years ago and then that noise just pops out of nowhere. And then it gets even better when the synth kicks in at around 5:00 and then the noise occurs again, but more quietly in the background. God I love that track.