I think its all in the feel of the keys.
edit:
When the tumblers move, it sounds like Waterhouse is shooting the main bolt on the Gate of Hell. It takes him a little while, and a few more false starts, to get his bearings; he doesn’t know how many numbers are in the combination, or which way he should turn the dial to begin with. But with experimentation, some patterns begin to show through, and eventually he works out the following combination: 23 right—37 left—7 right—31 left—13 right and then there’s a really meaty click and he knows in his marrow that he can take off the headphones.
- Cryptonomicon
