Why stop at the previous movie & soundtrack releases and the audiobooks?
BTW, there is an American dramatization of The Hobbit, too:
The Hobbit (1979) (Radio Drama) - Chapter 1: An Unexpected Party
"This radio drama adaption of J.R.R. Tolkien's The Hobbit is an abridged recording produced by The Mind's Eye (not to be confused with BBC's radio drama adaption from 1988) and directed by Bob Lewis. It was originally broadcast on National Public Radio (NPR) and have been distributed by Jabberwocky, Soundelux and HighBridge Audio/HighBridge Company on both cassette tapes and compact discs."
J.R.R. Tolkien - The Hobbit - NPR Radio Drama 
"In 1979 the US National Public Radio broadcast a radio dramatization of J. R. R. Tolkien's The Lord of the Rings. It was produced by The Mind's Eye and has since been made available by several different companies. ... The Mind's Eye also produced a six-hour adaptation of The Hobbit." -Wikipedia: The Lord of the Rings (1979 radio series)
There are ... videogames with lots of sound effects, music, dialog, and even cut-scene video:
The Hobbit (2003 video game)
The soundtrack was a free download released as advertising for the game.
And how about all those supposed "rip-off" "inspired by" CDs? Well, there is at least one that was never a rip-off ... just a musician's soundtrack if he were to compose one:
Music Inspired By Middle Earth by David Arkenstone
This one is not free -- be sure to buy it (independents need your support -- especially one so dedicated as to change his name to a Tolkien creation).