Note that getting these rings isn't as simple as the three quest chain indicated.
In order to GET the communicator in the first place (Moteha Windborn will replace it but only after you obtain it in the first place) -- you must complete a quest chain that starts at the Crash Site, coords above are correct.
Boktar Bloodfury will give you a short 5 quest chain:
First "The Missing Bronzebeard" followed by "The Nose Knows" and then "Sniffing out the Perpetrator." Upon return to the Crash Site, you are given "Speak Orcish, Man!" which leads to "Speaking with the Wind's Voice". This is a kill quest info at http://www.wowhead.com/?quest=12917 -- note that you can loot the relics for one of the other quests given at the Crash Site from the mobs who drop the "voices" (small items that look like motes of air) .
After the "voices" are turned in, you start a new quest chain, beginning with "Catching up with Brann" which then leads to "Pieces of the Puzzle", "Data Mining" "The Library Console" and finally, the last quest in this chain, "Norgannon's Shell".
Completion of "Norgannon's Shell" opens up the quest you probably came out here for in the first place, the one on this page: "Going after the Core" -- which has two follow ups, and then the nice blue ring, or rather choice of four blue rings, one of which should probably be a decent upgrade if you did this prior to level 80 and heroic runs or raiding.
Total of 13 quests to get the ring, along with any side quests that you do at the same time. Total time investment is approximately 1 1/2 to 3 hours, depending on class, level, drops, and whether or not you are soloing. Longer if you do the other quests at the same time, less time if you just pound it out, get lucky with drops (the "voices" dropped for me one every three or four kills, not one every other kill as someone else noted) or do it with a friend.
I thought I'd list and the quests and explain some of it because there is no indication of two quest chains prior to being able to start the one on this page --- Usually there is a note indicating any prerequisites and I always appreciate the information when it is provided. :)
Good luck. The quest rewards are rather nice and the ring is decent for starting heroics at level 80. I did the quests with a friend - we had no problems, hunter/shaman, both of us level 79. Some decent green quest rewards for selling or DE'ing, drops, and a nice chunk of exp in this zone (or gold if you're 80) make it worth doing.