Sound results from changes in air pressure. The human ear detects these changes as wavelengths, vibrating from forty to forty thousand times each second. They range from the quietest whisper to the explosion of a bomb.
The outer ear "catches" sounds and sends them to the inner, working parts of the ear. Without the outer ear we still would hear plainly, but many sounds would go by unheard.
Between the outer ear and the eardrum is a twisting canal. It is lined with hairs and wax that trap dust, water and even small bits of dirt or insects that could cause damage.
The eardrum is a membrane about one-half inch across. This is where the transmission of sound begins. As sound waves hit this membrane, it acts much like a drum, and the sound travels through it to the middle ear. This has three tiny bones connected together called the anvil, hammer and stirrup. These magnify the drum's vibrations by about twenty times. The tiny stirrup then taps it all against the fluid of the inner ear.
The inner ear is a hollow area protected by hard bone. It is filled with a watery fluid and contains the cochlea, a twisted snail-like tube. This is lined with thousands of sensitive cells, each of which responds to just one certain sound. When the fluid vibrates from the tapping of the stirrup, only the nerves corresponding to that particular wavelength 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. There are about thirty thousand of these circuits ready to respond! While each tone is kept separate from every other one, 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 the brain receives the messages in exactly the same way from both. This is another example of the wonders of God's creation. No human could ever invent anything like it nor could the body develop such remarkable parts by itself.
Since God has given us this remarkable sense of hearing, we should be careful how we use it. The Lord Himself said, "Take heed what ye hear" (Mark 4:2424And he said unto them, Take heed what ye hear: with what measure ye mete, it shall be measured to you: and unto you that hear shall more be given. (Mark 4:24)). He knew that many things would reach our ears, and we must learn to separate the good from the bad. And so He has invited you to "incline your ear, and come unto Me: hear, and your soul shall live" (Isa. 55:33Incline your ear, and come unto me: hear, and your soul shall live; and I will make an everlasting covenant with you, even the sure mercies of David. (Isaiah 55:3)). May each of us desire to hear God's wonderful Word, not just in our ears, but in our hearts as well.