Valve's Secret

In 2011, Valve relased the most famous game called Portal 2.
So in one test chambers there is distorted audio file by scientist Doug Rattman.
I was on Portal 2 Wikia just for fun, and then I went to Doug Rattman's page.
It said "voice actor unknown".
I couldn't believe my eyes! Who was (or what) was acting his voice?
Maybe it's a mixture of some other voices mixed in one,
Maybe that voice actor don't want to show himself up, but why?
I don't know this. Maybe you'll decipher it.
But to this day, it's still creeping me out.
{{by|CreepyGuy2033|cpwuser=yes}}