What makes a sound high or low?

Put your fingers on your throat and hum. Do you feel the buzz? Every sound starts with something wiggling back and forth. Scientists call that wiggle a vibration.

The wiggle pushes the air, and the air carries it to your ears as a wave. Inside your ear, tiny parts wiggle too, and your brain turns that into the sound you hear.

A high sound is a very fast wiggle. A low sound is a slower wiggle. Pluck a short, tight guitar string and it wiggles quickly, so it sounds high. Pluck a long, loose string and it wiggles slowly, so it sounds low.

Loud and quiet are different. A loud sound is a big wiggle. A quiet sound is a small wiggle. A sound can be high and quiet, or low and loud!