Freesound Forums

I really, really like the sound effects I'm hearing here, and I'm just wondering if I can legally use some of these effects in my music? Is that cool with anyone?

Yes, as long as you follow whatever license the uploader attached to their sound.

There are 4 licenses used on this site:

Creative Commons 0 ("Public Domain") gives you the most freedom; you can do whatever the heck you like with a sound that has this license since the uploader has effectively put it in the public domain. You don't need to credit the uploader if you use it, and you can make money off of it.

Creative Commons Attribution ("Attribution") has the same freedoms as "Public Domain", but you would need to credit/attribute the uploader whenever you use the sound. You can still make money on projects that use this sound, but only if you give the appropriate credit/attribution.

Creative Commons Attribution Non-Commercial ("Attribution Non-Commercial") is the same as the "Attribution" license, except it cannot be used in commercial projects; e.g. you can't use it to make money. And you will still need to credit/attribute the uploader.

The final license (now disused, but still available on older sounds) is the Sampling+ license ("Sampling+"), which is effectively the same as the "Attribution" license. You can use it in commercial projects, to make money, so long as you credit/attribute the original uploader.

How you credit the sound is usually up to you, but you should try to always include:
-The name of the sound
-The name of the uploader
-The website you downloaded it from
-A link to the sound

For example:

"Das Rheingold on Kazoo" by The_Incredible_Shredder of Freesound.org (www.youcantbeserious.com)

That pretty much sums it up. You can read more about it here:
https://freesound.org/help/faq/#licenses

Oh sweet Public Domain is awesome for me, and I like promoting people's creations I have no money however XD so.. I hope I can find some Public Domain stuff :3