The Spirits Have Voices shows that you have appeased the ghosts of the Thunderlord Clan by returning their artifacts.
<name>, now that you can see me, there is something you must tell Rexxar. I know that he seeks his people, and I know where they are.
The Mok'Nathal, as they are known, have a village to the east beyond the Razor Ridge.
Go, give Rexxar this news. His people are in danger, and I know that he will want to come to their aid.
You can only see Garm Wolfbrother when you have completed the quest . He should be right next to Rokgah Bloodgrip.
What is this you speak of?
Garm Wolfbrother? He was the last chieftain of the Thunderlord clan. If you have communed with his spirit, then it must be true.