How Is Sound Produced?
Sounds travel in waves. If you throw a pebble into a still pond, you will see ripples, or waves, spread outward from the point where the pebble hit the water. Sound waves are similar to these ripples.
Sound waves are made by vibrations. The complex internal structure of our ears can respond to the waves produced by vibration, whether in the form of bass drum or an acoustic guitar.
When you pluck a guitar, the vibrating string makes the surrounding air vibrate. These vibrations travel outward like ripples on water. When the waves reach our ears, we hear them as sound. No sound lasts forever.
The waves that carry the sound become weaker and weaker, and finally our human ears can no longer hear them. A variety of metrics are used to measure sound’s intensity, volume and pitch.
The pitch of sound is measured in hertz. One hertz (Hz) refers to the complete cycle of sound waves per second. Thus, 5,000Hz is equal to 5,000 cycles per second.
The human ear can generally perceive sound between 20Hz and 20,000Hz. Animals can often hear sound that humans can’t. For example, dogs can hear sounds at very high frequencies – often above 20,000Hz – but cannot hear low frequency sounds.