Welcome to the Music and Sound forum on GD.net. Pull up a chair, listen to some tracks by your peers and discuss all things music and sound. We're happy to have you. Please check out the FAQ link for some basic (and mostly common sense) approaches used in this forum. If you have any questions, feel free to PM me.
I've never heard of anyone successfully attacking a sound before. Sure, you could cancel noise out with special headphones, but that seems like it's defending against sound rather than attacking it. It doesn't seem like a sword would do much damage.
Ecoste - check out www.soundrangers.com and www.sounddogs.com for an a la carte method of purchasing sound effects. I'm sure there are tons of other options out there on the internets. Or if you can provide more information, like Moritz explained, then you could hire a sound designer here on GD.net. If you're not concerned about NDA - you could even post the animation of visual reference you're trying to support with a sound effect. Simply asking if there are sword attack sound effects is hardly enough information to go off of and actually be able to help you.
Nate (AT) MadsenStudios (DOT) Com
Composer-Sound Designer Madsen Studios
Cedar Falls, IA