While the sounds have been added to a new tab on existing database entries, they have also been given a searchable database all their own. In addition to this, Wowhead has put together a playlist feature that works in conjunction with the sound database. Users can now add their favorite tracks to a customized playlist that can be listened to on a new playlist page. If you decide you don't like a track, a quick click will remove it.
To celebrate the implementation of the new feature, Wowhead is also giving away 15 Moonkin Hatchling pets. While the feature is here for good, the contest only runs until 3pm EST Monday, December 23 -- you can get those entries in, as well as learn more about this cool new feature, on Wowhead's official announcement page.