Do hills/mountains reflect the sound of thunder, or does the sound originate so high that it makes no difference? I'm on vacation in a mountain village, and there was a thunderstorm happening, with most of the strikes seemingly behind the nearest hill, and they seemed very quiet (despite the sound coming quickly after the flash).
My family keeps telling me just old folk knowledge about how hills "carry" the sound, but I have no clue what that's supposed to mean.

Pic punrelated.