FWP:
For background see S. R. Faruqi's choices. For more on Ghalib's unpublished verses, see the discussion in {4,8x}.
Gyan Chand's text has not guft-o-shunuud but buud-o-nabuud , which seems a far less probable reading than Raza's, since it sacrifices the excellent wordplay and gains nothing in return; as always, I follow Raza. In this particular case Gyan Chand's text might have been carelessly conflated with his text of {3,8x}.
An enchantment [:tilism] is a magic world, a narrative concept developed to the highest possible degree in the Dastan of Amir Hamzah. An enchanted world in which no one could speak or hear, or at least no one did speak or hear, would be a fine realm for a hero to explore. But the speaker feels that either he's trapped in a cemetery, or else he's an 'alien' or 'destitute'-- no matter what the explanation, he's not a gallant hero but someone who's hopelessly isolated and alone. Either people in this enchanted realm neither speak nor hear (since they're literally or metaphorically dead), or else he himself is a kind of deaf-mute and cannot even hear their conversation, much less share in it; thus he himself is socially 'dead'.
Needless to say, without the wordplay of 'city of the silent' for 'cemetery', this verse wouldn't have a leg to stand on. While we're mentioning body parts, 'head to head' is a great touch, in a verse based on speech and hearing.
Compare Mir's more spectacularly radical use of the idea of a :tilism : M{1314,9}.
Gyan Chand:
shahr-e ;xamoshaa;N = a cemetery. For me, this world is entirely an enchantment. Either nothing told me of its reality, or else I was a stranger in this world. The gist is that I wasn't able to understand the language of this place.
== Gyan Chand, p. 65