answering machines as devices for not being reached

The one piece of communication technology in the brothers' room is engineered, on both ends, to hold contact at bay. Hal's honesty-week outgoing message accidentally tells the exact truth about where he's headed — a disembodied voice whose body "is not now able" — the coming voicelessness announced as a joke. And Pemulis's infinitely recursive machine is a deliberate filter: worn so thin no real caller will wait through it, which is precisely what he wants, since the whole design is to make sure no one who matters ever actually gets through.