FREEDESKTOP SOUND THEME LICENSES AND ORIGINS: See CREDITS RULES: Similar to those defined by gnome-audio, quoting Elliot Lee: The criteria for sound inclusion: . No licensing issues (https://fedoraproject.org/wiki/Licensing#Good_Licenses) . Appropriate length . Shorter than 1 second for any sound that denotes a specific event . Shorter than 5 seconds for a background sound (basically, startup/shutdown) . Appropriate sound . Volume . Normalized between samples . Spectral range . No extremes . Good taste . KISS . General common sense (hah!) Of course, in addition to this the Theming Spec not only requires normalized sounds, but those with with good perceived loudness as described in: http://replaygain.hydrogenaudio.org/calculating_rg.html PUT TOGETHER BY: William Jon McCann, 2008-2009 Lennart Poettering, 2008