God’s design of the human ear – Part 2
19:27 Stop listening to instruction, my child, and you will stray from the words of knowledge.
Yesterday, the outer ear. Today, the middle ear.
The function of the middle ear is to amplify the sound vibrations of the eardrum. the vibrations must be compressed into a much smaller area.
This is accomplished by a sequence of three small bones in the middle ear, known collectively as ossicles. The ossicles are the smallest bones in the body. They are the only bones that never grow larger from the time of birth.
Vibrations produced in the eardrum are passed to the first bone, called the hammer (malleus) whose “handle” is attached to the eardrum. This bone, in turn, passes its vibrations to a bone called the anvil (incus). Next, the vibration is transmitted to a bone that looks like a stirrup, called the stapes. Finally, the “foot place,” located on the stirrup, is inserted into a small oval window.
Amplification results because the surface area of the eardrum is much greater than the foot plate of the stirrup, thus concentrating the energy over a smaller area and resulting in over a 20-fold increase in pressure. The foot place moves in and out, like a piston, producing waves in the fluid of the inner ear.
How these bones know what to do is beyond me. The very fact that they never grow any bigger after birth is astonishing. How did evolution figure that one out? How did these bones know that if they worked together that they could transmit sound from the eardrum to…what? That’s tomorrow’s lesson: The Inner Ear. Prepare to be amazed (if you already weren’t).
Abba, as much as we depend upon hearing in this world, I am glad that we don’t have to depend upon hearing you audibly; You speak directly to our hearts and minds. May we listen for You daily as we train ourselves to listen closely for Your still, small voice–most of the time… Amen.