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Cochlear Implants And Hearing Essay Research Paper

Cochlear Implants And Hearing Essay, Research Paper


Introduction:


I decided to do a researched-based project. Since I was a young child I have


been fascinated by the Hearing Impaired. Recently there has been much


controversy in the Deaf community over the use of Cochlear Implants in pre-lingual


deaf children. I took this assignment as an opportunity to take a closer look into the


world of hearing aids and Cochlear Implants. Since I was in high school I have


known what I wanted to do with my life: Work with the hearing impaired to better


their communication skills. In order for me to fulfill my goals, it is important for me


to fully understand the devices out there that may or may not help a deaf patient


hear the slightest sound. There has been much controversy, as noted before,


because of the advanced use of the Cochlear Implant, in fact many members of the


Deaf community view it as an effort of the hearing world to fix the deaf world.


Many Deaf people do not wish to be fixed, nor do they feel anything is wrong with


them. I wanted to research this so I would be better equipped to make an educated


opinion of my own about the intentions of the Cochlear Implants being used in


pre-lingual children.


Findings:


I feel it important to start with the basic anatomy of the normal working ear.


Without knowledge of the basic concepts and terms of hearing the rest of the


findings will be rather confusing. First lets cover some key terms. An Audiologist is


a person with a degree and/or certification in the areas of identification and


measurement of hearing impairments and rehabilitation of those with hearing


problems (Turkington). The oval window is the tiney opening at the entrance of


the ear. There are three basic parts of the ear that will be covered in detail shortly:


the outer ear, the middle ear, and the inner ear. The middle ear is the small cavity


between the eardrum and the oval window that is home to the three tiney bones of


hearing. The eardrum is a paper thin covering that stretches across the ear canal,


separating the middle ear from the outer ear. The inner ear is the inside section of


the ear where sound vibrations are formed into messages that are sent to the brain.


Hair cells facilitate this because they are the tiney sensory receptors that transform


the messages to the brain. (Turkington) The ear as a whole is pictured below in


figure 1, and the three sections of the ear are explained in more detail:


Figure 1:


The human ear is divided into three anatomical divisions; the outer ear


which includes the pinnae or auricle and the external auditory canal; the


middle ear which includes the tympanic membrane (the ear drum) , the


middle ear ossicles (bones) named the malleus (hammer), the incus (anvil)


and the stapes (stirrup), as well as the cavity in which they are situated (otic


capsule); and the inner ear which includes the cochlea and the semicircular


canals. (Anatomy…)


Hearing aids are the age old remedy to hearing loss in varying degrees. A


hearing aid is a device that amplifies sound waves to help sounds be processed more


clearly. Hearing aides amplify sounds, helping a person hear better, but cannot


restore normal hearing abilities. Hearing aids will amplify ALL sounds, not just


those that the person wishes to hear. This results in much interference, which can


take some getting used to. (Turkington)


There are many types of hearing aids available, more than 1,000 different


models are available in the United States alone! Each type will include a


microphone to pick up the sounds, an amplifier to boost the sound level, a receiver


or a speaker to deliver the sound to the ear, and all are powered by some sort of


battery. Some people wear them in just one ear (monaural) or can wear them in


both ears (binaural). Hearing aids are divided into five different types: digital,


in-the-ear, in-the-canal, behind-the-ear, and on-the-body. The two most common


are in-the-ear and behind-the-ear models, shown in figure 2. (Turkington)


Figure 2


In-the-ear aids are lightweight devices whose custom-made housings


contain all the components; this device fits into the ear canal with no visible


wires or tubes. It is possible to control the tone but not the volume with these


aids, so they are helpful only for people with mild hearing loss….Because they


are custom-fit to a person s ear, it is not possible to try on before ordering.


Behind-the-ear aids include a microphone, amplifier and receiver


inside a small curved care worn behind the ear; the case is connected to the


earmold by a short plastic tube. The earmold extends into the ear canal.


Some models have both tone and volume control…. some people who wear


glasses find that the glasses interfere with the aid s fit. Others do not have


space behind the ear for the mold to fit comfortably. (Turkington)


The First step in preparing for a hearing aid is to have a medical exam and a


hearing evaluation. Through this exam, and audiologist can determine whether or


not a hearing aid will help, and which model will be the most beneficial. Hearing


aids can be very expensive, anywhere between $500 and $4,000, and are usually not


covered by most insurance plans. There is no known medical risk to hearing aids,


although some people choose not to wear them sometimes, complaining that


everything seems entirely too loud. (This is often due to the fact that the person has


forgotten how loud normal sound can be.) (Turkington)


Cochlear Implants are beneficial in restoring hearing in a profoundly deaf


patient whom cannot be helped by a conventional hearing aid. According to a


report of surgical results… the device is capable of restoring speech discrimination to


the extent that patients can once again carry on a conversation (Parkin) The


Cochlear Implant acts as an artificial human cochlea in the ear, aiding sound travel


from the ear to the brain. It is different from a hearing aid in that it does not


amplify the sound, it merely helps it to travel. Cochlear Implants are electronic


prostheses that transduce sound energy into coded electrical signals that bypass the


nonfunctioning or absent Cochlear hair cells and deliver them directly to the spinal


ganglion cells or axons of the Cochlear nerve. Proximal neural elements conduct


these impulses to the auditory cortex, thereby restoring the sensation of hearing.


(Callanan)


The Food and Drug Administration (FDA) has placed limits on those people


eligible for the Cochlear Implants. They have done this because they are highly


controversial, very expensive, and sometimes have uncertain results. ( The cost of


surgery ranges from $7,000 to $10,000, and the price of the device is about $10,000.-


Parkin) Only those people who receive no significant

benefit from hearing aids, are


atleast two years old, and have severe to profound hearing loss are eligible. A


typical Cochlear implant is pictured in figure 3.


Figure 3


All Cochlear implants consist of a microphone worn behind the ear


that picks up sound and sends it along a wore to a speech processor, which is


worn in a small shoulder pouch, pocket, or belt. The processor boosts the


sound, filters out background noise, and turns sound into digital signals


before sending it to a transmitter worn behind the ear. A magnet holds the


transmitter in place through its attraction to the receiver-stimulator, a part


of the device that is surgically attached beneath the skin in the skull. The


receiver picks up digital signs forwarded by the transmitter, and converts


them into electrical impulses. These flow through electrodes contained in a


narrow, flexible tube that had been threaded into the cochlea.


As many as 24 electrodes (depending on the type of implant) carry the


impulses that stimulate the hearing nerve. The brain then interprets the


signals as specific sounds. (Turkington)


Despite all the possible benefits of this procedure, many members of the Deaf


community argue that the benefits do not outweigh the risks and limitations of the


device. They are also concerned that this Implant will have the potential to make


their language, American Sign Language, obsolete. Because it is a surgical


procedure, medical risks are possible, such as dizziness, facial paralysis, or infection.


During the procedure, the surgeon will make an incision behind the ear to open the


mastoid bone that leads to the inner ear. The receiver-stimulator is placed in the


bone, and the electrodes are threaded into the cochlea. The operation can take


anywhere from one hour to five. It is impossible to guarantee a significant change in


hearing abilities. Many people describe the sounds they are able to hear as being


robot-like or artificial. This of course is a result of no medical breakthrough being


able to match the ability of a persons natural hair cells to transport sound to the


brain. (Turkington)


Most people whom receive the implant report being able to distinguish


medium to loud sounds, especially speech. Vincent Callanan reports that


Postoperative speech perception varies widely, although patients can be simply


classified as good or poor responders. Factors predictive of better performance,


irrespective of the device implanted, include younger age at the time of


implantation, a higher IQ, a normal cochlea on computed tomographic scan, and


better ability to lip-read.


The problem arises when Cochlear implants are used in children that are


prelingually deaf: those children that have not yet developed any meaningful


acquisition of oral language. Robert Crouch argues that the Cochlear implant is


intended to help the deaf child ultimately learn an oral language and, in doing so, to


facilitate the assimilation of the implant — using the child into the mainstream


hearing culture. When the child receives a Cochlear implant, he or she is put on a


lifelong course of education and habilitation, the focus of which is the acquisition of


an oral language, and ultimately, a meaningful engagement with the hearing world.


He does not argue that this is a horrible thing, however if the parents make the


decision to fix the child s deafness before he really understands it, the child is


separated from a part of their lives, their DEAFNESS. It is important that the child


be able to experience their true identity, and later in life, when the child is mature


enough and comfortable with themselves, it is then that the decision should be made


to receive the implants.


Crouch sums up his argument against Cochlear implants, saying While the


postlingually deafened person, once fitted with a Cochlear implant, can maintain his


or her present speech production capabilities and relearn to hear, the prelingually


deaf child using a Cochlear implant must be intensively taught and trained to


recognize and produce each vowel and consonant sound and each word from the


ground up. For the implant using prelingually deaf child, then, the path to oral


language development is a long and arduous one beset with many pitfalls, where


there seems to be no guarantee that the destination will be reached. Why put a


child through this with no real guarantees? Would it not be better to wait until the


child has developed enough to be emotionally stable and secure with themselves?


A child that is permitted to remain deaf can look forward to learning a


language as unique as their condition: ASL. Through this the child will have a


building block to learning and recognizing spoken language. They will share a


culture with people similar to themselves, and will be able to make a choice between


hearing and remaining deaf. I firmly believe that the battle of going from deaf to


hearing is a long and trying one, and the person should be old enough to understand


that before making the decision.


Conclusion:


I can understand how the prospect of the Cochlear Implants can appear to


be a light at the end of the tunnel for those parents who foster deaf offspring.


However, I do feel it to be very important to allow the child to first experience their


own culture before forcing the hearing world on them. The world of the deaf person


is rich with culture and history, believe it or not, and I believe that it would be easy


for a prelingual child to feel stuck between two worlds: the hearing and the deaf.


The child could very easily feel as if they belong to neither group. The decision to


use any type of hearing device, whether it be a hearing aid or a Cochlear implant,


should be the decision of the individual, when they are mature enough to


understand all the benefits, risks, and complications.


References:


Anatomy of the Ear


April 20, 2001.


(also source of Figure 1)


Callanan, Vincent. Cochlear Implantation for Children and Adults.


Lancet. 2000; 356(8999): 412-414. February 17, 1996.


Crouch, Robert A. Letting the deaf be deaf: reconsidering the use of


Cochlear implants in prelingually deaf children. The Hastings


Center Report, July- August. 1997. v27. n4. p14(18).


Larkin, Marilynn. Can lost hearing be restored? Lancet. 2000;


356 (9231): 744. August 26, 2000.


Parkin, M.D., James L. Multichannel Cochlear Implant Restores Hearing.


Am Fam Physician 1984; 30 (5): 249. November, 1984.


Turkington, Carol A. Cochlear Implants. Gale Encyclopedia of Medicine.


Edition 1. 1999. p740.


(also the source of figure 3)


Turkington, Carol A. Hearing Aids. Gale Encyclopedia of Medicine.


Edition 1. 1999. p1354.


(also the source of figure 2)

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