An aurora ring prevents negative effects of weather—specifically, confusion from hard rain as well as additional slowdown from snowdrifts—during overland travel, and always has "resistance to sound ##". It is a standard (but rare) type of ring, rather than a "Special" artifact, so each has a material type and may have additional attributes or enchantments, e.g. a gold aurora ring of resist sleep.
Aurora rings do not protect from etherwind; vindale cloaks and some Special artifacts do. Although they prevent random snowdrifts ("It's hard to walk on a snowy road.", etc.) from further slowing travel, walking over snow will still take more time than over other terrain.
Can be found randomly (very rarely), and can be received as a New Year's Gift from an adventurer who's at a relationship level of Soul Mate or above. Can also be wished for. If you're lucky enough to find more than one, the spare ones can be used to trade for expensive items adventurers have, especially if you use a blessed scroll of change material to improve its material type.
Miracle, even godly aurora rings can be found at well invested black markets or Moyer the Crooked's Shop in Noyel.