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)