The article will be useful to parents who are trying to explain physical phenomena to their kids and schoolchildren studying physics.
We all live at the bottom of the air ocean. And sound is also waves, only air. They cannot be seen, but easy to imagine. It is enough to recall the water surface during the rain. The waves diverge from each fallen drop along the water surface.
In the same way, air circles diverge from the sound source: a spoon that hit a glass, a slamming door, etc.
Sound can have a relatively frequent sound wave, and then its sound will be thin and high. However, the larger the period, the lower the sound we hear.
Mosquito often waves wings in the air (700 waves per second), thereby creating a high -frequency sound wave, which reaches a human ear in the form of a high squeak.
The fly waves its wings less often (350 waves per second), so the sound wave is a wider and smooth and human ear reaches a characteristic buzz.
Video: sound occurrence
