A professional skydiver set out to debunk 10 most common myths about skydiving in this neat article at The List Universe. For example:
9. The Freefall Chatter
Skydiving Myth: You can talk or yell to each other during freefall
Despite what you’ve seen in movies like Point Break and Cutaway, you cannot hear another skydiver during freefall. Perhaps if you were to yell into his year, you may hear a little but you certainly can’t have any type of conversation. The wind traveling past your ears at well over 100 mph pretty much makes you deaf to all sounds. Additionally, it would be very hard to fight during freefall as well.
From the Upcoming ueue, submitted by Jake.
just opening your mouth unprepared might give you a bit of a suprise =]