How bad is swearing in Battlefield bad company

It Battlefield: Bad Company, it is not terribly bad. A lot of 's' words are slid in here and there, and there is a massive amount of 'd' and 'b' words.
In BFBC2, the swearing is much worse. 'F bombs' are consistent and 'S bombs' come every couple of minutes.

I do not discourage you from buying the games, though - you can always turn the voices off.