Trout spawning video

Here's a short clip of some trout I filmed today.
This was with my new gopro 3.

I'm pretty happy with it so far. But what is that squealing noise in the video? It didn't sound like that on my computer. It only sounds line that on the YouTube upload

I like that perfect mirror that the surface provides -- neat effect.  Pretty fish.  I didn't hear any squealing when I played it.  Old ears? Dunno.