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Take Care Of Them Now Ears Don'l Many people spend hours on diagrams, instructions and articles that describe for them in detail exactly how a stereo or hi-fi works, and by understanding this, they're able to keep their sound systems functioning smoothly for their listening enjoyment. Few people, however, take time to learn anything about the parts that make up their own personal "sound system"?the human ear. A basic knowledge of how the ear works can help a person better understand the i need for protecting the ears from damage. ^ Unlike a stereo or hi-fi, with parts num\ bered so that replacements can be ordered, the ear cannot be "repaired" in this manner, but if properly cared for, it's designed to last a lifetime with the original parts. I It's compact, portable and requires neither batteries nor outlets for electrical current. When functioning properly, it brings the individual a range of sounds from a cricket's chirp to a full orchestra. Parts of the ear As shown in the illustration on this page, the ear "begins" with the outer ear, or the auricle. The auricle is basically made of carf ili/tA r\/-4 iaji + K rl/in rjn/H hoc n firm oloc. II la^c LUYCI CVI ty 1111 o rv 111 a 11 vj nao a i u 111, giajtic consistency. This part of the ear is believed to aid in the localization of sound entering the ear. Sound moves into the ear through the ear / canal and is enhanced by resonant characteristicsof the canal. The sound waves move M through the ear canal to set up vibrations of P the eardrum, also referred to as the tympa| nic membrane. If Behind this membrane is a cavity, called m- the middle ear. This part serves to increase the pressure of sound waves traveling t through the air into the ear. This must be done before the waves can enter the inner ear. Normally, low-impedance sound waves moving through the eardrum into the middle B ^ear are amplified about 21 times through the ^^Hterage action of the three middle ear Hbonesi the malleus, the incus and the stapes, commonly referred to as the ham rmer, anvil and stirrup. The footplate of the stapes bone, in turn, moves into and back from the part of the ear Four Join I K ^K * . B K^H Mk M ^P v ^^ K JH JBM b\ :^Bfl m ttmh Jack Cape Bailey Carding Employed 12/09/75 Retired 1/03/83 4 r Come Witi Auricle ' t #tL Ear canal _ \ Cartilage / Bone known as the oval window. This is the "entrance" to the inner ear, or cochlea. The movement of the stapes footplate causes a resulting motion in the oval window. This sets in motion the fluid that fills the cochlea. As the fluid moves, it stimulates tiny hairs which have nerve cells attached to them. It is the movement of these hairs which causes the cells to send impulses along the fibers of the cochlear, or auditory, nerve to the brain. The brain then translates these impulses into the sensation of sound. Types of hearing loss If a person is exposed to high levels of noise without ear protection over an exRetirement Group ^S^isinijiiifil i Mwkmm \ Glidy Holmes No. 2 Weaving Employed 7/10/48 Retired 2/28/83 h Replaceim MoWaua (Hammer) |ncus \ (Anvil) i\i i \ I 7/\ \ Eardrum (Tympanic membrane) Middle < tended pericxJ of time, there can be a noiseinduced hearing loss. In such cases, the damage is usually to the tiny hairs in the innAr ear It is also believed bv a number of medical experts that the hairs can be damaged by the use of such substances as alcohol and tobacco, and damage is known to be caused by some drugs, such as kanamycin, dihydrostreptomycin, quinine and neomycin. This type of hearing loss, known as sensori-neural loss, can also result from such diseases as measles, mumps, scarlet fever, whooping cough, influenza and certain other viral infections. A certain degree of sensori, A ?? Tk All Cn/4 UIai i no i uuy uiu tiui fl Carl Landers No. 1 Weaving Employed 9/16/63 Retired 12/31 / 82 Page 11 ent Parts Stapes ^ (Stirrup) / . Oval Window \ ? Cochloar narva 7V__ (Auditory narva) Cochtaa (Innar aar) \ " Mr cavity neural hearing loss can be expected from the natural aging process. This type can also be hereditary. The other type, conductive hearing loss, is usually associated with the outer or middle ear and is usually caused by a perforation or infection in the middle ear or an inflammation of the middle ear bones. Cleaning the ear deeply with objects such as a pencil or a cotton-tipped swab can result in perforation of the eardrum. For this reason, ears?exceot for the verv outermost oortion?should be cleaned only by trained medical personnel, and children should be taught from an early age never to put objects into the ear. rk Careers rr. , I,, i rtfTiic mnce Lydia Weaving Emp??ved 1/07/37 Retir . 12 31 / 82