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In many previous articles I have discussed ear problems and hearing loss issues, and I think it is time to revisit the basic structure of the ear. It is such a marvelous and sophisticated organ.
I am going to describe how hearing works and its magic we benefit from multiple times a day and take for granted — until something happens to our ears.
Your ears are an incredibly sophisticated and well-organized organ system that can detect low rumbles, bass noises as well as high-pitched electronic sounds and birds chirping, and take in and decipher the different and complex sounds of human speech and environmental noises.
The ear works in conjunction with the brain. The brain has centers that receive information from the ear and can tell you where sound is coming from. This is accomplished through having two instruments to gather sound.
Your ear, the external portion, collects sound, thus the reason it is shaped the way it is and transmits these sounds to the brain which acts like a computer and processes all these signals. If sound is on your right side, it will arrive to the brain via the right ear sooner than the left ear and will be louder, thus allowing the brain to make decisions such as which way to turn and look to locate the source of that sound. This simple process occurs, for example, if you are in a shopping mall and someone calls out your name.
The external ear, including the ear canal is an open passageway for sound waves to travel to the middle ear. The eardrum is a very tight surface comprised of skin that vibrates when it is hit by the sound waves, much like striking the surface of a drum as done in music.
When the eardrum vibrates and moves it transmits sounds through three little bones that are connected to each other and act like a hydraulic dampening system. This includes the malleus, which is commonly called the hammer; the middle bone is the incus, which is commonly called the anvil and the third and final bone that butts up against the inner ear is called the stapes or, as it is also commonly known, the stirrup.
Conditions in the middle ear are regulated by the eustachian tube, a passageway that connects the middle ear to the back of the nose. When functioning well, it will maintain equal air pressure on both sides of the eardrum so it can vibrate properly. This area is frequently affected by colds, viruses and allergies, and when not functioning well is treated with antibiotics and ear tubes, which is one of the most common procedures for small children.
The sound vibration enters the third and final part of the ear, the inner ear. The inner ear is composed of semicircular canals, three of them on the left and three of them on the right, which act as gyroscopes. They are fluid-filled structures that detect motion and help you with your balance.
The other part of the inner ear is called the cochlea, which looks like a snail shell.
It, too, is filled with fluid and has microscopic hairs called cilia. These hairs are sensory for hearing and they move when the vibrations disturb the fluid, much like dropping a pebble in the water and causing a rippling effect.
The cilia sway in response to the sound waves, which are converted to electrical signals carried through a hearing nerve, called the auditory nerve. These signals travel to the brain centers where this information can be processed and understood.
So, as you can see, the hearing is a sophisticated, organized and well-orchestrated organ system that provides us invaluable information, allowing us to communicate with friends and loved ones as well as protecting us from danger by giving us an early warning signal and allowing us to react appropriately.
We all know as we get older we may lose some hearing, but it is important to protect this organ system from loud noises so we do not have premature hearing loss. Typically, once you lose your hearing, you are not likely to get it back.
Denis Grillo, D.O., FOCOO, is an ear, nose and throat specialist in Crystal River. Call him at 352-795-0011 or visit CrystalCommunityENT.com.