system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does everyone have such a distinctive voice when all our parts in that part of the throat are so similar?
gpt
The difference is due to “timbre”. It’s the same reason you can tell the difference between the sound of a piano, a guitar and a trumpet even if they are playing the same note. The different shapes of the instruments affect the resonance of each one (the different overtones and frequencies that come through in their sound) 

Natural variations in the size and shape of humans resonating spaces (throat, sinus cavities, mouth etc) produce the same differences in timbre from person to person. That’s why you can recognize voices by their sound quality.