This is a simulation of how sound waves enter your ear, causing your eardrum to vibrate and stimulate nerve endings so you can hear.
To try this
simulation:
Use your mouse to either left-click or right-click (tap) on the tuning fork.
What's Going On?
This is a model of the human eardrum. As you tap on the tuning fork, you are creating a sound. The sound waves are conducted through the air into the ear, vibrating the eardrum in the human ear. As the sound waves push the eardrum in and out, a lever attached to the center of the eardrum wiggles back and forth. The wiggling lever stimulates the "nerve endings", allowing you to see the frequency and period of the sound that the model eardrum heard.
There's More!
This model demonstrates an important principle necessary for human hearing to work: Sympathetic Vibration. When an object in air vibrates, it sends out sound waves in all directions. Anything that the sound waves hit is affected by those vibrations.
If an object (such as an eardrum) is struck by the sound waves and is sufficiently compliant, the object will vibrate in sympathy with the original sound waves. This starts the chain of conduction through the various parts of the ear until the nerves sense the vibrations and we perceive the stimulus as sound.
Sympathetic vibration is key to how some musical instruments work. A guitar string by itself does not make a very loud sound. Neither does a piano string. The wooden body of the guitar and the internal wood sound box in a piano utilize sympathetic vibration to make the soft sounds louder.
