I'd say you get used to it. You really hear the larger pieces early. The larger the piece, the better you here it coming. And I'd say it hardly happens *just so*. Rock fall is considered as an 'objective danger', but objective is often subjective, in the sense of being capable of not putting oneself in some situations.
Please share your thoughts. Here are some of mine :
Earthquakes are quite objective, though there are regions with more. They are maybe not foreseable, but when it starts it may continue, hour, day, week, month. In parts of the Julian Alps, summer 2004 was f.i. an earth quake season.
The next thing that is considered as objective, is the spring rock fall due to snow melting and letting rocks loose. But we honestly can avoid that (OK, to a certain extent) by avoiding outings in that period. In any season, snow letting loose of rocks in the morning may be avoided by earlier starts (night approach), and eventually getting down early enough to avoid the mid afternoon slosh.
Chamois and ibex. That's a tricky one. An ibex won't attack if it feels secure, they're often just careless. But chamois will sometimes shoot rock on purpose, even if feeling secure and out of reach. If they wan't to, they manage to evolve without disturbing a pebble, so when you get stoned by chamois, you should know they're aiming at you.
People are the worse. Most rock fall endangering people happens because of other people (rock drag, carelessness, sloppyness, 'the path crossing above part of a wall' vs 'the wall above a path'.)