Bradbury says that Montag feels the pressure of the Hound's silence rising.How does this echo the description of Montag burning his own parlor walls?

My take is that Montag is silencing these vapid walls that spew forth an endless drone of nonsense. As the walls burn, they are quiet. This puts Montag on edge because he is used to the walls talking all the time. Similarly, Montag expects the Hounds to be looking for him, not hearing them puts him on edge.