Select Page
Sound. Do our ears hear or sense it?

26 Jan, 2021

Binauraal geluid in Utrecht

What is sound?  

In physical terms, any action doesn’t make a sound. It creates high- pressure waves that spread in every direction.  When they reach our body, they only affect our ears by vibrating the eardrums. The characteristics of the vibrations change in electrochemical impulses. When the brain senses them, it translates them into sound. We do not hear sounds, we sense them.

High and loud  

Two main characteristics of sound affect the ear, pitch and volume.

Pitch describes how low or high is a sound we hear. Is it a low pitch cow mooing or a high pitch bird singing? It is related to how frequent or how dense are the high-pressure waves in a second. The human ear listens to frequencies between 20Hz and 20,000Hz. A 20Hz frequency vibrates the ear 20 times in a second. A 20,000Hz sound corresponds to 20,000 vibrations per second. A low and a high pitch sound.

Volume has to do with how loud or quiet a sound is. The higher the intensity of the wave the bigger the vibration of the eardrum, thus the sound is louder. The intensity of a wave reduces as it’s transmitted further away from its source, thus it sounds less loud. We measure volume in decibel. For every increase of 10db, a doubling in loudness occurs.

Real-life example  

Adele singing acapella on stage. While singing, a series of vibrations of her vocal cords create high-pressure waves. The frequency and intensity of each wave depend on the pitch and volume of her voice. As the waves pass through the air, they vibrate air molecules back and forth. Likewise, each wave vibrates the eardrums of her audience back and forth. The information is sent to the brain as an electrical impulse, which is interpreted as sound.


Soortgelijke artikelen

Soortgelijke artikelen