Ears - Their Structure and Care

e we can hear the sounds of music or any other sounds because of our remarkable organs of hearing our ears how do we hear the sound of this Bas vile for example we hear the sound because vibrations caused by the strings are conducted through the air these vibrations are converted to nerve impulses by our ears this is how we hear all sounds when we think of the ear we usually think of the part we can see but let's look at the entire ear in this model the ear extends deep into the skull where the ears delicate internal parts are protected by dense bone the entire ear consists of three distinct sections the outer ear the middle ear and the inner ear which contains the actual organ of hearing the outer ear has two parts the Oracle and the external auditory canal the Oracle is the part of the ear outside the skull it direct Sound Vibrations into the auditory canal which leads to the eardrum this is a thin delicate membrane which seals off the end of the canal the eardrum is protected from dirt and insects by tiny hairs and wax producing glands in the auditory canal when excess wax builds up in the canal only a physician should remove it probing for the wax with an object can easily damage the canal or Force wax against the eardrum usually excess wax can be washed away because it tends to work out toward the open end of the auditory canal when the canal is clear Sound Vibrations reach the eardrum and set it into vibration behind the eardrum is the middle ear which contains the three tiniest bones in the human body we can get an idea of their size by comparing them with the point of a pencil because of their shape the bones are called The Hammer the Anvil and the stup in the middle ear these three bones are joined together the hammer is attached to the eardrum and linked by the Anvil to the sterup the sterup fits into and covers an opening called the oval window which is part of the inner ear the inner ear is filled with a liquid just below the oval window is another opening the round window covered by a flexible membrane as the ear vibrates it moves the three bones the stup moves in the oval window setting up vibrations in the fluid in the inner ear notice that each time the stup pushes in the membrane covering the round window is pushed out by the fluid this equalizes the pressure in the inner ear pressure is kept equal on both sides of the eardrum by a tube called the ustan tube which leads from the middle ear to the throat the eustachian tube allows air to enter or leave the middle ear riding in an elevator can cause differences in air pressure on the two sides of the eardrum for example as we rise in an elevator outer air pressure decreases but because pressure has remained the same in the middle ear the eardrum is pushed outward yawning or swallowing will open the normally closed end of the ustan tube equalizing the pressure again ustan tube also makes it possible for infection to reach the middle ear for this reason a cold or throat infection may affect our ears blowing the nose gently will reduce the danger of forcing infected mucus from the throat into the eustachian tube and then to the middle ear we have seen that sound vibrations pass through the outer ear to the eardrum then to the bones of the middle ear and then to the fluid of the inner ear in the inner ear the vibrations reach the actual organ of hearing the inner ear has two main parts the spiral-shaped ccka filled with fluid converts vibrations to nerve impulses that are carried to the brain by the auditory nerve the second main part of the inner ear is made up of the semicircular canals these contain our organs of balance and are not concerned with hearing a cocka about the size of a p is a winding tunnel a cross-section shows us several sections of this spiral tunnel which is divided by membranes into three canals in the center Canal is the actual organ of hearing this is called the cockier Canal it is lined with about 25,000 hair cells each containing an ending of the auditory nerve tiny hairs grow from these cells as the fluid in the ccka vibrates the hairs are moved according to one Theory touching this membrane causes impulses to be sent from the hair cell into the auditory nerve and along it to the brain and we hear now let's see how all the parts of the ear work together sound waves are caught by the Oracle and directed along the auditory canal to the eardrum which they set into vibration the middle ear bones transmit the vibrations to the liquid in the ccka in the ccka the vibrations are changed to nerve impulses and transmitted to the brain the ccka is probably the most sensitive of all the parts of the ear it can easily be injured by Extremely Loud sounds jet engines for example produce sounds of such high intensity that men who work near the engines must wear heavy ear coverings to protect the delicate ccka also in the inner ear are the three semicircular canals which are at right angles to one another these organs of balance also contain hair cells the cells lead to this nerve which is joined to the auditory nerve as our head moves it causes fluid in the canals to change position stimulating the nerve endings of the hair cells the impulses from the semicircular canals together with the impulses received from our eyes and muscles enable us to keep our balance so the pleasant world of sound exists for us because of the delicate structure of our ears to be sure they are functioning properly it is a good health Habit to have regular hearing tests hearing may be accurately tested by an audiologist using an audiometer a device that produces tones of varying pitch and volume the patient's responses to the tones from the audiometer can be shown on a chart to indicate the range of hearing for each ear loss of hearing may result from many causes the most common cause involves the middle ear bones these bones must move freely to transmit sound vibrations to the inner ear but sometimes this movement is restricted as the joints of the bones gradually stiffen which impairs hearing this condition is called otosclerosis an ear doctor or autolist can detect and easily treat minor ailments of the year for more serious conditions ear surgery May sometimes be used to restore hearing but in many cases a hearing aid is effective to help restore normal Hearing in a person from the many types of hearing aids available an audiologist or autolist can select one that is best suited to the particular hearing problem sometimes loss of hearing May develop so gradually that we may be unaware of it unless we have regular checkups good hearing lets us enjoy the world of [Music] Sound by practicing the proper habits of hygiene we can ensure the good health of these remarkable organs of hearing the ears