Free Sound Project

http://www.freesound.org/index.php

Free sound effects. This site is crammed full of them and they are extremely authentic. Mostly natural sounds but also mechanical and digital sound effects and compositions.

You don't need an account to listen to any of the sounds but you will need one to download them. It's free to sign up and very easy to do.

This can be used for students to source sounds to use as part of a sound design. I have downloaded sounds, combined them using Aviary Music Editor and used the final mix as a stimulus.