The New Enemy?

Ok during “The Making of Halo 4: First Look” Trailer, when the guy (forget his name) said he wanted to introduce the new enemy, a sound that was high pitched was heard during what he was saying:

Click here to here it:

Is it just a sound effect or is it the sound that the new enemy makes?
Anybody know what it is?

I thought the same thing.
I hope we see the new enemies before E3.

> I thought the same thing.
> I hope we see the new enemies before E3.

Me to, it would suck to wait 3 more moths till e3 :frowning: