Board Thread:Questions and Answers/@comment-26285368-20150805211311/@comment-16461120-20150812061938

Having read the first three issues of Inhumans: Attilan Rising, it's pretty clear that Blackagar from The Voice Unheard isn't Medusa's Black Bolt from Earth-616.

Now, the Black Bolt from Earth-616 was exposed to Terrigen Mist while still in the womb, but if the Black Bolt that owns The Quiet Room didn't undergo prenatal Terrigenesis, then his voice wouldn't be destructive.