why are crowds louder than small groups/individuals even if each person produces the same amount of noise? In other words why would a group of people, each generating noise at Xdb sound louder than an individual generating noise at Xdb? How does cumulative sound work?
In: Physics
Same reason 2 horses can pull more than one. The power is cumulative.
Sound is just waves of pressure. High pressure followed by low pressure.
It’s more complex than this, since it’s logarithmic among other reasons, but to make it simple, let’s say that a person makes a sound that is at a pressure of “4” above ambient pressure in the peaks of the waves, and “4” below in the troughs. Add another person making the same sound at the same volume at the exact same time, and you get waves of “8” above and “8” below. Those waves move your eardrums twice as much as the single person’s “4” wave.
Interestingly, because it’s waves with peaks and troughs, it’s actually possible to cancel out a sound by generating the exact same wave, but basically upside down, so that any trough lines up perfectly with any peak, and as we know 4 plus negative 4 equals zero.
Latest Answers