Someone else mentioned in this thread, and I think this is a good point, that focusing on how the voices were alike was preventing people from focusing on how they were different.

I really don't hear too many differences between the two voices, other than superficial differences that it would seem could easily be altered by someone attempting to fake another voice (higher pitch, contrived teenage girl mannerisms, etc.).

Even if Fayla isn't PE, her voice always sounded way too cutesy in a fake sort of way to me to buy that this was a real 15 year old girl.

And the fact that ButtonNose shows up only days later only confirms it for me; what are the odds of two actual young teenage girls just happening to randomly discover this board within days of each other? I hardly think there are that many teenage girls searching for pedophile message boards out there. It seems to me ButtonNose was created simply for Fayla to have someone to play off of, so that Fayla could create the illusion more quickly that she was who she said she was.

The two different mics was a big point, as Cirk points out above. Also, a part that I failed to notice, the lack of compression. Fayla's "p" and "s" sounds DO indeed "pop" like blowing into the microphone, but PE's don't do that (or don't do it nearly as bad). I hadn't noticed that until it was pointed out, but that's a HUGE difference right there :)

Is it that hard to believe that the same person might have simply been using different recording equipment each time? It doesn't even have to be something that was consciously planned; the person could've simply been using different computers.