what's this instrument?

If you listen to this song, there's a high note repeated on every odd beat (it starts after a while).. it sounds very reverberated.. i don't understand what that instrument is..

http://www.youtube.com/watch?v=BkC5zMMifr8

maybe that effect comes from more than one instrument, (drum + woodwind ?)

I have no clue, any idea is appreciated, even if completely wrong :)

bye

Sounds like it could be a few things - first things that stuck out to me was a slapstick and a police whistle. Also could be something like a brake drum or similar metallic object with like ringing quality, hard to tell without hearing it on it's own. Marius would have a much better idea than I on this.