Audio problem: McKay is talking to Sheppard about the differences between himself and Rod, and at one point says that maybe Rod screwed up and was chosen for "a one-way ticket to another universe", yet his lips form the word 'galaxy'.
Audio problem: In the scene in the hallway when Sheppard and Teyla are dressed in hazmat suits and talking to Dr Weir via the intercom, you can see a reflection in Teyla's helmet of Sheppard's mouth moving, but there's no sound. (00:23:45)
Audio problem: Teyla's audio sounds way more high pitched then normal, either dubbed or a post production mistake. (00:06:00)
Answer: Those are actually suits that protect from hazardous chemicals. They are cheaper for the prop department and look nearly the same as biohazard suits. A real biohazard suit would indeed have a helmet that seals to the neck.
Grumpy Scot