Nabi (Sallallaahu Alayhi Wasallam) said, ?Whenever a Muslim passes by and greets the grave of someone when he knew in this world, Allah returns the soul of the deceased to his body so that he can reply to the greeting.?
The abovementioned Hadith proves that the dead are able to hear. However, it also proves that only those who Allah permits that they should hear will be able to hear. While the Hadith tells us that Allah Ta’ala returns the soul, hence, they will only be able to hear the speech of one with the permission of Allah.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai