I am sure that those of us who are blessed with the sense of hearing are thankful for our ears. As we learn more about the ear and the neurophysiological and mechanical aspects of hearing, we are made to realize that it is every bit as complex as the eye, and our appreciation is deepened for the divine design behind this most sensitive of all human sensory systems.

Anatomy of the ear. The ear consists of outer, middle, and inner parts. The outer ear is the visible portion which includes the skin-covered flap of cartilage known as the auricle and the auditory canal which leads to the eardrum (tympanic membrane). The middle ear contains the auditory ossicles, the three smallest bones in the entire human body—weighing only 10 mg. altogether. They are so tiny that if a person were to squeeze all three of them between his thumb and forefinger, they would be unseen. Because of their shape, these bones are known as the hammer, anvil, and stirrup (or the malleus, incus, and stapes).

Inside the skull, protected by hard bone, is the fluid-filled inner ear. It contains the cochlea, a twisted snail-like tube used for hearing, and the vestibule which houses the organs of equilibrium. The cochlea is divided into three canals—the vestibular, tympanic and cochlear canals. The basilar membrane, which forms a partition between two of these, houses the organ of Corti. Anchored in the Corti structure are as many as 25,000 hair cells. These sensory hearing cells are connected to the auditory nerve.

The hearing process. The fact that the shape of the outer ear with its ridges, hollows, bulges, curves and grooves, plays a part in the hearing process is a fairly recent discovery. All of these provide pathways for sound to follow, enabling us to fix the location and distance of the sound heard.

The hearing process begins when sound waves enter the auditory canal and strike the eardrum, a membrane about one-half inch across which is capable of handling over 73,000 vibrations per second. When sound hits the eardrum, it causes movement of the hammer, anvil, and stirrup. The vibrations of sound are magnified by about twenty times as they pass over the ossicles and enter into the small opening in the inner ear. Without this amplification, we would be deaf, since about 99.9% of sound would be reflected back out the ear. It would be like trying to talk to someone who is under water. This is the ingenious job of these amazing bones in the middle ear. They have been designed to take sound energy from the air in the outer ear, amplify it, and transfer that energy into the fluid-filled inner ear structures.

There, in the Cochlea, changes in pressure caused by this compressed fluid pushes down on the basilar membrane on which the organ of Corti rests, moving the hair cells. These hair cells are of varying length, similar to the strings of a harp, and each one responds to just one certain sound. When the fluid vibrates from the tapping of the stirrup, only the hairs corresponding with that particular frequency rise up to wave back and forth. When this takes place, a small electrical signal is made and sent to a corresponding circuit in the auditory nerve which carries it instantly to the brain. Since each tone is registered separately, confusion could easily result with so many sounds arriving at the same time. And yet, in a remarkable way, our brain separates everything into its proper order and makes it intelligible. All of these processes are done at the same time by two ears, and still the brain is able to distinguish the sounds in a crowded, noisy room.

Another amazing feature of the ear is the range of volume which it can handle. It is estimated that the human ear has a range of 10,000 to one. In other words, we can hear something which is very, very quiet and yet have the capability to hear another sound 10,000 times louder. To protect our ears from such loud noises, the Creator has equipped us with two tiny but amazing muscles called the tensor tympany muscle and the stapedius muscle. They are connected to the ossicles in the middle ear and dampen the bones depending on the intensity of the sound to protect the ear from permanent damage. Just as a drum player stops the resonance of his drum by pressing his hands on the drumhead, so these muscles dampen the stirrup bone—before we even hear the sound!

Our hearing is designed to be more sensitive to high pitched sounds than to lower ones. If it were the other way around, we would be able to hear the sounds of our internal organs as well as the blood rushing through our veins. The ear is designed so that there are no blood vessels located in the area where vibrations are converted to electrical impulses.

Men have learned much from the design of the ear to help them build systems which receive and transmit sound. However, nothing made by man can come close to matching the capabilities of the ear. To have any doubt about the origin of the ear or to suggest its amazing design is anything other than the handiwork of our Creator-God is to deny His very existence. The Bible, God's Word, clearly states, "The hearing ear, and the seeing eye, the Lord hath made even both of them" (Proverbs 20:12). Scripture is also very clear that the Lord wants us to use our ears to hear His Word—"Incline your ear, and come unto Me: hear, and your soul shall live" (Isaiah 55:3). To "hear" in Scripture means not only to listen to His Word, but also to receive it, to believe it, and then to obey it.

The words He wants us to hear are words that bring everlasting life. The first thing we need to hear is that we are doomed sinners—"All have sinned and come short of the glory of God" and "The wages of sin is death" (Romans 3:23; Romans 6:23). Then, we hear the good news that God sent His beloved Son into the world to pay the debt we owed by giving Himself as a sacrifice for our sins on the cross of Calvary (John 3:16). By hearing His Word, and believing that Christ died in our stead, we accept Him as our personal Saviour and thus pass "from death unto life" (John 5:24). Use your ears today to hear His Word.