Rats? Mice? The gnawing of a nocturnal mammal thriving on garbage? Upon closer inspection, it was nothing living -- what a curious relief, to learn that a noise does not come from a fellow being! -- rather, it was the wind rattling a door on a latch that left too much leeway. It had to be the wind since the trees moved outside.
R., we call him, jammed a knife beneath the door to stop it from moving. Yet, silencing one sound often invites more subtle ones to command our full attention. In this case, it was the refrigerator and, after its plug was pulled -- never mind the puddles in the morning! – there was an ever so subtly dripping faucet in the bathroom, audible still through the closed door.
Finally, after placing three wash clothes under the faucet, he heard the ultimate noise: the noise of his heartbeat, the unstoppable whirring behind his eyes, the ticking of age.