I believe we have more than one voice on PB. Take a listen to “How to Pronounce Cache”: (http://www.youtube.com/watdh?v=_rCcV6MiQZ0). This voice sounds almost nothing like the PB voice used in most of the other videos. Also, (I might be wrong on this one) but I believe the voice on “How to Pronounce Pneumonia” is also different (possibly because he had pneumonia): (http://www.youtube.com/watdh?v=EWh90XkWTM4)
I’m sure there are more but these were the first I noticed that sounded odd, particularly “Cache.”
https://soundcloud.com/english-pronunciation - this guy sounds like one of them. he is also stuck in a radio...