The process of hearing sounds is not as simple as sound waves passing down a tube to the brain. There are canals, bones, membranes, secretions, nerves, and even fine hairs involved in the hearing process. The causes for ringing in the ears can be just as complicated often confounding sufferers who are never given an exact diagnosis for their tinnitus. Understanding the nature of sounds, the inner workings of the ear, and the nervous system's role in hearing, will help when it comes to an understanding of the reasons for ringing in the ears.
Sounds are caused by the movement of molecules either liquid or gaseous. It is the vibration of air molecules that our ears pick up and register as a sound. Whenever air molecules are made to vibrate, by the snapping of fingers, the vibration of vocal chords, or the sudden shock of a bomb blast, a sound is created that spreads out in a wave-like motion. As the sound spreads out like ripples on a pond, it causes more and more molecules to vibrate but the vibrations get weaker as they travel outward. This is why sounds get weaker as they travel farther from the source. Humans hear a sound when the vibrations fall within a certain range of frequencies, too high and a dog might be able to hear it and too low and an elephant might register the sound but not us. Some people are sensitive to certain frequencies of sounds that can cause them to develop ringing in the ears usually on a temporary basis. Treatments for ringing in the ears need to be based on whether the cause is due to actual sounds or on falsely perceived sounds.
Sound waves entering the outer ear are funneled toward the ear canal then down to the eardrum. Glands in the ear canal, produce sticky earwax that gradually builds up in the canal and acts to trap dirt and small insects that can enter the ear. It also acts to water proof the inside of the ear canal thus helping to prevent mold and fungus from growing there. A buildup of earwax can block the ear canal leading to a loss of hearing but is easily removed with a proper earwax removal kit or by a physician. Normally there will be no problems with earwax buildup as it will dry up forming flakes that fall out of the ear.
At the bottom of the ear canal is a membrane that separates the outer ear from the workings of the middle ear. This membrane, the eardrum, acts to pick up the vibrations of air molecules and then like the skin stretched over a drum head, reverberates to the sound. The eardrum is easily damaged and can be ruptured by extremely loud sounds or sudden changes in air pressure. It can be torn or scratched by swabs or probes being used for cleaning the ear, thus the doctor's warning to never put anything into the ear smaller than your elbow. Earwax can get on the eardrum and become stuck to it, even drying out to form a hardened mass that can cause tinnitis. Any damage to the eardrum, because it transmits sounds to the middle ear, will affect the ability to hear. Fortunately the eardrum can heal itself with even ruptures and tears eventually healing. An aging eardrum can in some cases, lose its flexibility, gradually becoming stiffer and unable to vibrate causing hearing loss.
Attached to the inside surface of the eardrum is one of three small bones positioned in the space called the middle ear. These small bones are the Malleus (the hammer), the Incus (the anvil), and the Stapes (the stirrup), named after their function or shape. The eardrum connected hammer bone, acts to transmit sound waves to the anvil by striking against it. The stirrup transmit sound waves from the anvil to the surface of the cochlea which is a fluid filled, spiral shaped vessel that plays a role in both hearing and balance. Any damage to or abnormal growth of any of these small bones can cause hearing problems such as tinnitus. The normally gas filled middle ear is connected to the back of the throat by the eustachian tube. This tube drains any built up fluids and allows the air pressure inside the middle ear to fluctuate so it matches that outside the ear. If the eustachian tube becomes blocked or pinched, fluids can build up in the ear causing infections and swelling and pain in the ear. An extreme buildup of fluids or pressure can lead to a ruptured eardrum. One treatment method used when blocked eustachian tubes cause repeated infections, is the placing of small tubes through the eardrum that will allow fluids to drain and pressures to equalize.
The fluid filled cochlea has areas lined with tiny sensitive hairs that respond to vibrations coming in through the stirrup bone. Like the hairs on the skin, these tiny hairs affect nerves causing them to fire. Nerve signals travel through the auditory nerve to the brain where they are decoded as sounds. On one side of the cochlea there are three arch shaped, semi-circular canals, partially filled with fluids. The canals extend in different directions, vertically, horizontally, and diagonally in relation to the axis of the body. How the fluids line up in these canals tells the body how it is orientated at any one time thus creating a sense of balance. Exposure to overly loud noises or repeated exposures to high pitch noises can damage the tiny hairs or nerves of the inner ear. These damages can cause the nerves to fire constantly thus creating a ringing in the ears when there is actually no sound.
One positive aspect of the complexity of the hearing process with there being so many possible causes of tinnitus, is that there are an equal number of possible treatments for ringing in the ears. First an examination to find out which part of the auditory system may be causing the tinnitus is necessary. If a cause is found treatments may include, surgery, medications, dietary changes, herbal supplements, noise suppression techniques, earwax removal, stress management, white noise generators, and/or in the ear sound masking devices. If a definite cause cannot be found and the tinnitus does not clear up on its own, then there are several different medications and numerous supplements that can be tried on a trial basis to find one that helps. Unfortunately many cases of ringing in the ears are never fully diagnosed and no cure can be found.
Pressure applied to the parts of the ear or to the region of the brain where sound is decoded can cause hearing problems including tinnitus. Pressure can be caused by inflammation in the ear or the surrounding tissues such as the jaw muscles or teeth, swelling due to fluid buildup or internal bleeding, or from the growth of tumors in or around the ear or the brain. The many different tissues, bones, membranes, and nerves involved with hearing all require nourishment, with the blood system delivering the proper minerals, vitamins, and nutrients. Deficiencies or excesses in certain minerals, vitamins, and medications can all affect the hearing and lead to ringing in the ears. The pumping of blood through the vessels of the ear means that blood pressure can affect hearing and because of the fluids needed in the inner ear, dyhydration can effect hearing.
I hope that reading this article gives some insight into the workings of the ear and just how complicated it can be to find the ultimate cause for tinnitus. A better understanding should help when it comes to asking a doctor questions about treating tinnitus and curing ringing in the ears.