We can hear because of sound waves bouncing off our ear drums. Vibrations in the air travel down our auditory canal and hit against the tympanic membrane, also known as the ear drum. From there the vibrations are passed on to malleus and the incus, both bones. They then hit against the smallest bone in the human body, the stapes. These three tiny bones in the ear amplify the sound by about 30 times. The stapes then vibrates against the fluid filled cochlea which passes the movement on to the nervous system and to the brain where it is interpreted as sound.
Sound Waves On Your Ears Experiment
To see how sound can actually create vibrations in a membrane get a wide-mouthed glass bowl and stretch plastic wrap across it very tightly. It must be tight or this will not work.
Now toss a few grains of rice into the middle of the plastic wrap. Bang a pot loudly very near to the bowl and watch the rice jiggle and move as the sound vibrates the plastic wrap. Have the kids make other noises and yell near it to get it to move also.
Sound hits your ears in the same way. Brains are wired to interpret the vibrations as sound.
- For a different type of wave action make an ocean in a bottle.
- Sound waves are physical waves, that is they require stuff (air) in order to transmit energy. When we yell, the air doesn’t move much but the energy we let off our vocal chords sure gets transmitted. Learn about other kinds of physical waves like water waves and earthquake waves.
- Hearing is one of our physical senses; learn about the others as well.