I'm stumped. The note block and the arcane ear are both on identical material (dirt over cobblestone over void). Both are set to Note 7 (I've tried all kinds of numbers). They're obviously within range. I've tried punching the note block and applying a redstone signal - no matter what I do the arcane ear doesn't respond to the note.
I don't see anything in the Thaumcraft configs disabling it ...
I don't see anything in the Thaumcraft configs disabling it ...