From Raw Deal:
I always said I like talking to a sharp guy. You don’t waste breath. Precious thing, breath.
When people think of the soundtrack to 2001: A Space Odyssey, they think of Richard Strauss’ Also sprach Zarathustra, but the soundtrack is suffused with the sound of breathing, which is what I think of. The breathing in the space suits, in the space pod, as Dave decommissions HAL9000, and in the final scene, as the old man Dave meets his end.