system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does more sound also make sound louder?

For example, why does ten people talking sound louder than one person talking, instead of just being the same noise-level, just with more types of noises?
gpt
The amount of "loudness" is determined by the amount of energy that is shaking your eardrum. The more energy, the louder it is. There's a difference between how loud the same energy level of different pitches seems, but for now we'll just consider two people talking which is close in pitch so we can ignore that factor.

Coming out of each mouth is a pattern of pressure waves, they pass through the air and shake your eardrum. The thing is that they interact - adding together. If the pressure bit of both meet you get more pressure, likewise with the low pressure bit, if the opposite bits meet you would get less variation.

Because the sound of the two people talking isn't a constant, uniform wave, we don't just get cancellation. We get a more complex combined wave pattern shaking our eardrums that has more energy. So it seems louder.

The pattern though is not "twice the energy, twice the volume" it is more of a "10 times the energy, twice the volume" thing.