Ears to Hear
Ears to hear "The hearing ear and the seeing eye, The Lord has made both of them" (Proverbs 20:12). By means of a marvelous mechanism, God gives us the ability to hear. As I speak, my diaphragm, vocal chords, throat, mouth, teeth and tongue move in intricate ways to produce a complex of sound waves, vibrations in the air. A message is being sent! Can you hear it? Are you listening? A funnel-shaped cup on each side of your head catches the sound waves and enables you to know the direction of the source. The waves swirl around and enter the ear canal. The delicate skin on this canal grows outwardly at 2 or 3 mm per day to continually renew itself. The outer section of this canal is coated by a water-repellent wax-like substance which traps dirt and helps to keep water out of your ears. The inner part of the canal does not have this substance, which is why you should never poke a swab into your ear, or the wax may be pushed back too far and block the canal. When I was a boy, my father warned me not to put anything other than my elbow in my ear. The back of the ear canal is closed off by a membrane called an ear drum. The sound waves of my voice strike this membrane and cause it to vibrate. Thus, the air vibrations are converted into mechanical vibrations. Attached to the inside of the ear drum, there is a lever system composed of three small bones. They transmit the mechanical vibrations to the footplate, which is in direct contact with the fluid in the inner ear. Thus, the mechanical vibrations are converted into fluid vibrations. To equalize the pressure on both sides of the ear drum, a tube (the eustachian tube) runs from behind the ear drum to your throat. Swallowing helps balance the pressure. The inner ear converts the hydraulic vibrations into nerve impulses. The outer section of the inner ear, called the vestibule, is also used for balance and orientation. Operating something like the water tube in a level, it lets you know which way is down, and gives you a sense of motion, which is your sixth sense. Spinning around causes this fluid to slosh about, which makes you dizzy because your brain no longer knows which way is up. The sensors in the vestibule are also used to keep the visual image in your brain "right-side-up" when you tilt your head. The back part of the inner ear is a coiled duct, shaped something like a snail shell. It contains an extremely complex system of nerve fibers which can detect frequencies from 20 cycles per second to as high as 20,000 cycles per second. The physical processing of such a wide range of frequencies is an amazing engineering feat, especially since it is done in a mechanical device the size of a pea. The decreasing diameter of the coil, causes the wave crests of the various frequencies to strike the walls at different places, which enables the nerves to report reception of that particular frequency to the brain. 23,500 sensors send these signals to the brain through the acoustic nerve which is a bundle of about 30,000 individual fibers. These fibers are grouped according to frequency, and the intensity of a sound is indicated by the number of fibers carrying the sound. These signals go to different parts of the brain, where the signals from the two ears are mixed, decoded, insignificant signals are filtered out, and significant signals are acted on and stored in memory. Thousands of different creatures have ears specifically engineered for their own needs. The ear was made by God (Proverbs 20:12). It did not evolve, it could not, not in a hundred billion years. How well do we use these marvelous ears God has given us?