system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are voices unique?

Everyone has a different, distinct voice with varying tone, pitch, thickness, clarity, volume etc. Why is that?
gpt
Humans produce sound by forcing air through a complicated series of vibrating flaps and chambers. Possible differences in the size and shape of those flaps and chambers are so numerous that it is highly unlikely for two sets to ever be exactly the same. These differences are what give each voice unique characteristics.