The Wonder of Hearing
by Whit Sasser
God’s design of hearing is such a wonder of the human body and our ears in particular. "The hearing ear and the seeing eye, the Lord has made them both" (Proverbs 20:12). Our world is full of sound—sirens, traffic, thunder…songbirds, music, voices, etc. Thank God, we can hear!
I have read that sound waves are patterns of disturbance caused by the movement of energy traveling through the air from a source…some object that causes a vibration, such as a ringing telephone, or a person's vocal cords. This in and of itself is a marvel of creation. These sound waves then enter the outer ear and travel down the ear canal to the eardrum causing it to vibrate.
The middle ear, behind the eardrum, contains three small bones, one of which is the smallest bone in your body…and it never increases in size, as do other bones in the body. These bones amplify the vibrations and send them along to the cochlea, or the inner ear, a fluid-filled structure that looks a little bit like a snail. How can we hear a whisper or a mosquito flying? Because the sound wave pushing on our eardrum is amplified by as many as 180 times as it travels some two inches through our ear system. Amazing!
Next, the inner ear fluid causes sensory receptors, called hair cells, to move. Depending on where they are in the cochlea, these hair cells pick up different pitches of sound. As the hair cells move, microscopic projections on the hair cells bend to open channels. Chemicals fill these channels turning sound waves into electrical signals which then travel up the auditory nerve to the brain. And all this happens instantly without you having to yet think about it! Wonderful!
The brain then interprets the information it gets from the ear and attaches meaning to it, so it makes sense and gives us information about our environment. It processes the time variation it took for the sound to reach your left ear as opposed to your right, allowing us to judge the direction a sound is coming from. Amazing!
Our brain analyzes the pattern of sound waves picked up by our ears so that we can know whether we have heard a horn or a bark or a voice. And it is remembered. I recall when I lived in London when walking among tall high rise buildings, I would hear jet planes passing overhead before seeing them. The sound of the Concorde engines was different than other commercial jets, and I would hear first, then look up, knowing this one is a Concorde before seeing it.
I could go on and on and on about the wonder of our emotions attached to the sounds of beautiful music, the intelligence gained by hearing words, the fear and alarm that comes from certain sounds. Praise our awesome Creator!
