Why is there a wave in the sea shell?

Put a large shell or shell in your ear, you will hear the soft waves of the sea. However, the vast ocean cannot get into that small shell. so what sound?

The answer is that you are listening to the surrounding noises but have been transformed based on some principles of physics. The following 3 factors can help you better understand.

First , shell types act like a 'resonant device' (device that resonates) .

Put the shell in your ear, you will hear the sound of the ocean.

When pursing your lips through the empty bottle, you will hear the sound of a note reflected from the inside of the bottle. We often call it 'bottle' , but in scientific language, it is called 'resonance chamber' . All types of shells have a concave convex shape, which is unusually small and small so its sound reflection will appear at many different frequencies.

Conducting research in a rather noisy room, the experts placed a cup near the ear (because the cup's interior is much simpler than the shell) and attached a very small microphone right behind the eardrum. The microphone recorded a sound of 15dB at the resonant frequency of the cup of 648 hertz. And at twice the frequency (1296 hertz), the audible sound is 16dB.

However, in order for the shells to produce ocean sounds, the surroundings must have noises. If you go into a soundproofed room and put the shell on your ear, you will definitely not hear anything.

Second , the human brain is quite excellent in imagination. We can see animals floating in the clouds, visualizing the face of Jesus appearing in a piece of potato, even Mary on a sandwich.

Third , people live in a sea of ​​sound, but most do not pay attention. This is similar to sometimes we just feel socks or underwear for a short time after wearing them. And throughout the day, their awareness of their appearance will no longer exist. In the same way, our brains often ignore noise.

The combination of the ear and the brain has changed the sound that enters. The brain tries to explain the origin of this new noise because you are or are near the sea, and so it is the "ocean wave" that is coming.