system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come when you crack your knuckles underwater, it is incredibly loud, but when you try and scream underwater, the sound is muffled to a whimper?
gpt
Water transmits sounds quite well, so if an action vibrates the water to make a sound, you'll be able to hear it clearly in the local area. However, sound does not cross mediums very well. When you're trying to talk (or scream) underwater, the sound is being generated by vibrating air in your vocal chords. When this hits the water just outside your mouth, only a little of that energy is transmitted into producing underwater sound waves. The rest is lost, reflecting back into your mouth.