What we hear is because of sound. Sound is a wave, not a radiation but also a form of energy, and we’ll talk about its properties below.
Why does sound appear?
To start, touch your throat and speak. Do you feel it vibrating? That is sound energy. Anything that vibrates creates it, but we cannot hear in some places. That is because the energy needs molecules to spread out and get into your ear.
Also, have you ever heard of the speed of sound (Mach 1)? That’s how fast sound energy travels in a certain environment which depends on the media’s density and temperature. The faster the molecule moves and touches another, the faster the energy transports. Mach 1 in dry air at 20º is approximately 343 m/s.
Interestingly, if an object exceeds the speed of sound in that area, it will make a shock wave — a sonic boom.
How to make sound?
It’s effortless because even a slight movement creates sound. First of all, when you walk, you make a sound when your foot is traveling through the air, and make a louder one when it lands. This is because the air around you compresses and expands and releases the energy by sound. Playing musical instruments also makes the thing vibrate by the right method so that it can make organized music, not annoying noise.
Reflection and refraction
Well, remember that sound is waves, and it can reflect and refract too. Have you ever heard of an echo when you clap in a large room? That is because the sound reflects on the surface of the wall. What’s more, some animals and equipment use sonar to detect things, which finds the time of the echo and the slight change from the original voice.
Also, you know hearing your voice in a recording can be stressful, right? Well, that’s the sound you emit being refracted by the bones in your head. That same phenomenon also causes you not to hear properly in water, although the your voice is
The sound you can hear
The sound you can hear only accounts for a tiny fraction of all the combinations of vibrations in nature, like Light. They are also measured in wavelength but in a different approach so they use hertz (hz). A human can hear down to 20 hz and up to 20,000 hz.
Also, sound levels are measured in decibels. It is a logarithmic scale so if you add 10 decibels to the noise, it will be 10 times more intense. Surprisingly, your ear can probably sense as quiet as 0 decibels. Also, exposing to over 70 decibels excessively on a daily basis can damage your hearing.
Furthermore, do you know sound could be deadly? If you are exposed to more than 200 decibels, it can mess up with the internal organs and possibly cause death.