system
Given the following post, respond as if you're commenting on Reddit:
human
Why does closer thunder sound sudden and sharp, while distant ones are more drawn out?

I thought the cause may be that different frequencies in the sound of thunder are carried at different speeds through the air, but wouldn't that mean I would be able to hear a difference in pitch?
gpt
Mostly because of echoes/difference in path lengths. The farther you are away from a lightning bolt, the more chances the sound has to bounce off a few things (or not) before reaching you. The more a sound bounces around, the longer its path length, and the longer it takes to reach you. So, some of the sound goes directly to you while some of the sound bounces around a bit before reaching you. The different bits of sound from the original lightning strike reach you at different moments, so as a whole it sounds longer and more drawn out. 

You can experience this same effect on a smaller scale. Stand in a very large, empty field and yell to a friend. There is very little opportunity for the sound to bounce around, so the sound either goes straight to you or gets lost out in the sky. As a result, your friend's voice sounds sharp and quick. Then go into a small canyon and yell to your friend. All the bounces the sound can take makes it more drawn out. The audio world calls this "reverb".