Lecture # 108:
Hearing Loss

copyright 2008 Cheryl K. Hosken, BSN, MS Psych.

Objectives:
1. The student will understand how a baby is evaluated for hearing loss.
2. The student will know the various technologies used to help people hear.
3. The student will understand techniques used in assisting the deaf to learn.

New Developments in Hearing
Jean Kleppe couldn't hear her dog's bark or the gong of her large clock in the living room. She started going deaf at age 40, like her mother did. For the next three decades, her loss of hearing became greater than the power of hearing aids to help her. Her doctor advised her to abandon the external hearing aids and try a prosthetic audio implant. She immediately signed up for the operation.

The name of the prosthesis is cochlear implant. It consists of three parts: a microphone placed behind the ear (picks up sounds), a speech processor often worn on the person's belt (converts sounds in to electrical signals), and a surgically implanted receptor which stimulates neurons in the cochlea (send impulses to the brain). Doctors can now significantly enhance hearing in 80% of their patients, and even children who are born deaf are candidates for the implant procedure. Children need to be treated within the first five years, before the brain loses its ability to process sound. Albert Maltan who is the president of Advanced Bionics says, "We are reaching a point where we can restore hearing [to that] of normal people - where we can actually cure deafness."

The idea of electrically stimulating the auditory system is nothing new. In the 18th century, an Italian physicist, Count Volta, hooked two metal rods to his famous invention and the battery, and put them in his ears. The sound was like the boiling of a thick soup. By the 1970s, scientists had discovered that such electrical impulses needed to be near the groups of hair cells which convey tone and pitch of sounds. Today's devices have 24 electrodes that stimulate different patches of neurons through the hair cells.

The results are not perfect. People with the implant say that voice have a metallic quality, like hearing a radio broadcast. Also, hearing all the various tones of an orchestra is difficult. In loud environments, many people lip-read to complement their new hearing. The surgery is expensive - about $50,000. In the next few years, it is hoped that the technology and surgical procedure will lead to decreased costs. For those with insurance, the company usually pays for the surgery.

For patients like Jean Kleppe, it is worth every penny to hear. Four weeks after the implant surgery, she was shown how to clip the microphone behind her ear and change the batteries in the speech processor. Then the doctor activated the implant. Thirty minutes later, she and her friend are walking around talking and laughing about her new gift of hearing.
(Taken from Newsweek Magazine, June 24, 2002, by Brad Stone)

Meditate Word By Word On These Verses:
Mark 7:31-37.

A Day in the Life of Chris
On Tuesday, at 6 A.M., Chris' dad shakes him awake. They say "good morning" to one another and Chris heads for the shower. After a quick breakfast and a look at the paper, he is ready to go to school. He drives his own car there and is cautious to look twice before every turn. The volume on the radio is at maximum but he can barely hear it. Other drivers stare at him and his noisy car.

At school, he goes to the student council meeting room. It is now 7 A.M. and time for their regular monthly meeting. His sign language helper talks briefly with him before the meeting starts. The helper is a marvel to Chris because she signs everything that people say, even when they are talking all at the same time!

Chris then has English and gives his paper comparing the poetry of Tennyson and Byron. During his study period, he goes to the speech therapist. She asks how his work in school is going and if he has problems because of his inability to hear. They work on sounds - letters "s" and "z" are difficult for him.

In the next class, he has a different interpreter. It is biology and Chris will work on dissecting a frog today. The interpreter is not happy about this project! Then Chris goes to the school newspaper office to edit feature writers' articles and work on page layouts.

At day's end his eyes are tired from watching interpreters. But he has energy to do some homework after school. Student note takers have helped by sharing carbon copies of their notes with him. There are 5 interpreters for 10 deaf students in Chris' school.

At dinnertime, Chris talks with parents out loud, who can understand his speech. In school, he does not use speech because it is not a normal type of voice. His parents sign to him - for practice using their skills. After dinner, he goes to his room for study. He takes a break after an hour and enjoys some tunes with a beat to them. He "hears" the beat through the vibrations of the radio that sits on his lap. He calls a friend on his TT, a telecommunication device for helping deaf people converse, watches the captioned news on TV and goes to bed.

Question:
1. How does Chris cope with his hearing loss at home and at school?

 

 

Defining Hearing Loss
Have you watched two people signing to one another? Did you assume that at least one of them was completely deaf? Although that may have been true, very few people with hearing loss are completely deaf. Because of degrees of hearing loss, there are two different definitions:

Deafness - hearing impairment that is so severe that a child is impaired in processing the spoken word through hearing, even with amplification. This situation adversely affects his educational performance. Being deaf means that hearing is disabled so that understanding speech through the ear alone or with a hearing aid is impossible. Chris can still feel and enjoy the beat of music, even if he does not understand all of the words.

Hearing Impairment - a permanent or fluctuating impairment that adversely affects a child's educational performance, but not with the severity of deafness. With a hearing impairment, speech can be heard, with or without a hearing aid. As a child grows, his speech becomes more intelligible because he can hear somewhat.

We identify degrees of hearing loss as slight (difficulty hearing a whisper, or words with "f" and "s" in them), mild (child needs preferential seating near the teacher and some speech therapy), moderate, severe (difficulty hearing the barking of dogs, telephone rings, or piano music) , and profound (needs specialized help and interpreters).

Characteristics
Communication - The greatest communication barrier associated with deafness is language use. To be defective in language, for a human being, is one of the most desperate calamities, for it is only through language that we enter fully into our humanness and culture, communicate freely with others, and acquire and share information.

People who are deaf or hard of hearing use one or more of three main approaches to communication.

  1. Oral/Aural: speech/reading skills (oral) in addition to remaining residual hearing (aural)
  2. Manual: sign language only
  3. Total Communication: a variety of communication types including formal signs, informal gestures, and spoken and printed words.

Students vary in their communication characteristics. Professionals and families often have their own preferences about the type of communication method they believe is most appropriate.

Social Characteristics
Helen Kellor said, "Blindness separates people from things, but deafness separates people from people." Certain behavioral differences occur because people who are deaf view the world through their eyes more than their ears. For example, people who are deaf and hard of hearing need to gaze closely, and appear to stare at face, lips, and hands of the speaker. They also use their hands and bodies to communicate and at times may touch or tap to get someone's attention. Sometimes hearing people think these behaviors are rude.

Some students who do not use sign language may develop undesirable social skills. Because they have difficulty with reading others' lips and understanding what has been said, they talk all of the time and conversation BETWEEN people does not occur. No one likes conversation dominated by one person.

If students can successfully communicate with other students, they will benefit socially. There are programs to help hearing children learn sign language for better communication. Signing is introduced through games and short phrases that children can easily learn.

Question:
2. Why is deafness such an overwhelming problem?

 

 

Educational Characteristics
Students who are hard of hearing are typically underachievers in both reading and mathematics. Students who are deaf have trouble with vocabulary, syntax, and figurative language including idioms. But they also have the same distribution of intelligence as hearing people do.

Children with no hearing loss learn English structure, grammatical nuances such as prepositions and pronouns, by the age of three; their language is stable after the age of six, and their language habits are hard to change after the age of 13. Obviously it is important to diagnose hearing loss early. Only if children are identified and receive early intervention will they learn the language that is the basis of reading. Reading is the primary avenue for students who are deaf to gain information in school, work, or society.

Causes of Hearing Loss
The ear consists of three parts: the outer, middle, and inner ear. Sound goes into the outer ear, is changed to electrical impulses in the middle ear, and is transmitted to the hearing center of the brain. The ear is like a radio system: the inner ear is the radio receiver, the middle ear the radio station transmitter, and the outer ear a microphone in the studio. To be effective, all must work together. Hearing loss occurs when some part of the ear is not functioning. There are two ways this can happen: through conductive hearing loss and sensorineural hearing loss.

Conductive hearing loss is caused by some problem with the outer or middle ear, the inner ear is not affected. The hearing loss is not caused by lack of sound perception, but by lack of sound conduction. When fluid collects behind the eardrum in the middle ear and becomes infected, the result is an ear infection and conductive hearing loss.

Sensorineural hearing loss is sometimes called nerve deafness. It is caused by problems in the inner ear or along the nerve pathway from the inner ear to the brain stem. With sensorineural hearing loss, the receiver (inner ear) is not working. Even though the microphone picks up the signal and the transmitter conducts the signal to the receiver, no reception takes place and no sound is heard. A hearing aid will amplify sound but cannot correct a sensorineural hearing loss.

Hearing loss that occurs before birth, in early childhood, or before exposure to spoken language is called "pre-lingual" or pre-language. Of those who are deaf, 95% have this type of hearing loss. "Post-lingual" is the term given to hearing loss that occurs after a child has been exposed to spoken language. These children are the remaining 5% of deaf children.

Causes of Pre-lingual Hearing Loss
Premature Birth - A premature birth with low birth weight causes an increase in bleeding in the brain, which may cause deafness.

Heredity - There are 150 forms of genetic hearing loss and these include syndromes involving other characteristics. These account for about 50% of children with hearing loss in the moderate to profound category. It is recommended that families with hearing loss get genetic counseling for young people who want to marry.

Viruses - Maternal Rubella virus causes deafness in fetuses before birth. There is a rubella vaccine available that can be given to young women of childbearing age.

Congenital Cytomegalovirus - This is a herpes infection that can be acquired through the placenta of the mother during birth or through her breast milk.

Post-lingual Causes of Deafness
Children with post-lingual hearing loss have the advantage of having heard and perhaps used spoken language. Because they retain some memory of sound, their language development is not so greatly hindered as that of children with pre-lingual hearing loss.

Meningitis - This is an infection of the central nervous system that may extend to the brain and the ear. Usually the hearing loss is profound or progressive.

Otitis Media - This is an infection of the middle ear that is common in young children. Almost all children will have three or more infections of the inner ear by their third birthday. When a child has frequent ear infections, it is important to have a speech and language evaluation as a baseline for the future. Delays in speech or language may occur during these infections. Prompt medical treatment including antibiotics or surgical placement of tubes in the ear helps the situation.

Unknown Causes - In these cases, there may have been a momentary lack of oxygen to the brain that caused hearing loss. There is no way to find the answer.

Match these terms with the definitions below:
A. Pre-lingual hearing loss,   B. Post-lingual Hearing Loss,   C. Nerve Deafness,   D. Middle Ear Infections.

3-1. Common infections in young children that may affect hearing.
A, B, C, D.

3-2. Loss of hearing after a child has learned to speak.
A, B, C, D.

3-3. Loss of hearing before a child has learned to speak.
A, B, C, D.

3-4. Deafness caused by signals not getting to the brain from the inner ear.
A, B, C, D.

 

 

How is Hearing Loss Determined?
Hearing problems need to be detected as early as possible in order to plan an appropriate educational program. Nurses in birthing hospitals are usually the professionals who survey expectant mothers to determine if there are risk factors for hearing loss. If the newborn infant has an identified risk factor (low birth weight, or a history of deafness in family, need for intensive care) through this screening, a hearing assessment is scheduled.

In Chris' family, his physicians did not suspect a hearing problem. They were concentrating on the delays in his physical development. If newborn screening had been done, Chris' family would have known earlier about his hearing loss and received help through an early intervention program.

Usually infants that have a risk factor are screened 1-4 days after birth. If the results are not clear, the infant is re-screened again at the age of 4-6 weeks. If the infant fails this screen, a diagnostic evaluation is done to try and determine the cause of deafness. If the results are positive for the behavioral audiological evaluation of hearing loss, early intervention programs are started at the age of six months.

To determine if the baby hears, an auditory brain stem response test is done. This means sensors are placed on the baby's head and in the ear, computer clicks are sounded, and the baby's responses are measure by the computer and an audiometer. A new method had been developed recently. When a sound goes into the ear, it strikes the eardrum and goes through the middle ear to the inner ear. There, thousands of hair cells vibrate and a signal to the brain. These hair cells also send an echo back through the middle ear. An audiologist can measure that echo sound with a microphone placed in the baby's ear. By the measurement, he can know how much sound is getting to the nerve that sends a signal to the brain.

Question:
4. When should a baby be evaluated for hearing loss?
(Only one of the following answers is correct.)
a) at birth and when there is a family history of deafness.
b) a few days after birth when family history is positive for deafness.
c) when there is prematurity.

 

 

For older children, a behavioral audiological evaluation is used. You have probably had one of these tests yourself. You put on earphones and tones ranging from high to low are given. When you heard the tones, you pushed a button or signaled with your hand. During such an evaluation, an audiologist usually places the child in a soundproof booth for the testing. Some audiologists now invite the whole family to watch the process. The family members fill in the results of the audiogram on graphs. In this way the whole family can understand and see the results immediately since they are actively involved in the testing.

The audiogram shows frequency and intensity of sound. The frequency means the number of vibrations that occur in one second. A high sound has more vibrations. We commonly think of the highness or lowness of a sound as a pitch. Intensity is the pressure of a sound, not its movement. The intensity of a sound is measured in decibels, named after Alexander Graham Bell. Sounds are measured from silence to very loud. for example, a whisper is 20 decibels and a jet plane when it flies upward is 130 decibels.

Chris' audiogram showed that he hears only very loud noises at 90 -110 decibels. He also has more hearing in the lower frequencies. Without his hearing aid, he is at the bottom of the audiogram. With his hearing aid on, he can hear 50-60 decibels in his left ear, which is his better ear. Normal conversation is about 60 decibels so that Chris can hear normal speech with his left ear and a hearing aid. Although he is able to hear speech, the sounds are like the sound of a radio that is not tuned in fully on a frequency. He can hear and tell the difference between a man and woman's voice, rock or classical music, a dog's bark, and the noise of a washing machine. He cannot hear the telephone ring because the pitch is too high.

Without hearing aids, Chris hears from 90-100 decibels in his left ear, and in his right, 105-110. This means he hears only at lower ranges of the hearing scale and hears better in the left ear than in the right ear. If you tried to communicate with Chris, on which side of his body would you stand? If he is in a classroom sitting at a desk, where would you place him?

About 30% of students who are deaf have other disabilities. Of particular importance is the lack of vision. To be sure that vision is intact is of utmost importance. If there are motor or cognitive delays are present, therapeutic professionals need to also identify them.

Question:
5. An audiogram shows ____________ and ____________ of sound.

 

 

Determining the Nature and Extent of Special Education
Those people who are around a deaf child gather information about him so that plans can be made to educate him. These people are his family, teachers, relatives, and friends. These people give information about his communication with others. Some of the questions may be:

  1. How does he communicate?
  2. To what extent does the child talk with others at home or at school?
  3. When he answers questions, does he need the help of the interpreter to voice what he signed?
  4. Does he voluntarily try to speak or communicate or does he respond only if spoken to directly?
  5. How does the student respond when called on in class?

For example, Chris' interpreter notes that he seems to be more comfortable when talking with small groups like his biology lab group. A normal sized classroom is not a situation where he readily talks even though he is a bright student. In addition, other team members can help to identify Chris' needs and strengths. The speech therapist can give information about Chris' ability to make himself intelligible to others. the audiologist may report that Chris' most recent testing shows that his hearing levels are stable (not wяorsening) and Chris' hearing aids will not need to be changed. Because Chris hears low sounds better, male teachers may be more understandable to him than female teachers.

Chris himself is also an important source of information. For example, he prefers not to sit in the first row of the classroom because he sees the interpreter and teacher better from the third row. At he has progressed through high school, Chris has been more interactive with other students, because by knowing his problem they try to understand him.

What Should Students be Taught?
Often, grammar and speech instruction are the most important parts of curriculum for a student, but then there is little time for academics and deaf students never achieve academic levels that will help them in life. If we want to educate these children, then their academic goals should be nearly the same or the same as those for other students. At the present time, there are specialized curricula available. Perhaps the most famous is that of Kendall Demonstration Elementary School at Gaullaudet Univerisity in Washington, D.C. and the Alexander Graham Bell site for deaf children. (Website addresses:
https://www.personal.kent.edu/~hjohnson/991217B_files/frame.htm,
https://www.agbell.org/information/brochures_idea.cfm)
There are doubtless curricula available in other countries' education systems, but I am not aware of them.

Those who work with the deaf have the following choices in the teaching of deaf children:

For language and speech development, small children can learn the basics of language as hearing children do. This is done through play activities from the immediate environment. Another approach is for older children who can analyze the structure of grammar. Basic language patterns are taught and them expanded into more and more complex structures.

What is the best way to teach children who are deaf or hard of hearing? This is an enduring debate. Some people use the oral/aural method, meaning using the voice for speech and the individual's hearing capacity for reception of sound. This teaching depends on two abilities: enhancement of hearing through reading of lips and dependence on residual hearing. Because capabilities are different in every child, hearing aids and assistive devices are necessary to hear. Attention of the student is focused on the speaker's face and acute listening.

Additionally, students vary their communication in different situations. For example, Chris communicates with his parents and good friends. However, in a noisy classroom with many different speakers and vocabulary, he uses the assistance of a sign-language interpreter.

Other deaf and hard of hearing people communicate only through manual mode or sign language. In addition they may mouth the words they are saying and use other gestures as well. Then there is total communication: formal signs, informal gestures, finger spelling, facial expressions, mime, body language, and spoken or printed words. All people, hearing impaired or not, use signs and speech at the same time to communicate. Among themselves, though, deaf people use sign language.

To help with instruction, teachers can use an overhead projector that also puts light on their faces and helps the deaf child to lip read. Use of slides with written out text is also a help for the deaf. To modify classrooms, lighting should be good and light on the teacher's face helps. A swivel chair helps a deaf child to follow conversations from one group to another. Carpeting can reduce noise so the child hears better.

There are also Personal FM communication sets that work on radio waves and deliver speech directly from a microphone worn by the teacher to the receiver in student's ear. This eliminates background noise, and provides the clearest and most consistent pattern of the teacher's voice. The FM microphone should always be placed next to the sound source, e.g., other students or a TV, when the teacher is not talking. For ease of management, you should have a second microphone for this purpose.

Question:
6. How can deaf children be taught?
(Select the best answer.)
a) through all means - gestures, sign interpreters, hearing aids, mime, etc.
b) according to the child's capabilities.
c) by the parents' choice.

 

 

Where should Deaf Students be Taught?
In order to help the child with deafness fit into his community, many think it is best to educate him in the local public school with support of interpreters, note takers, and tutors. Resource rooms for special speech or listening training are provided for those students who need more help. There are day programs for them in special schools in large cities. There are also residential schools where students stay during the week. Often these students have a positive experience because the school faculty knows how to sign, there is greater participation in after school activities, and ease of socializing with others. However, studies have shown that students in regular schools achieve more in reading and mathematics because they are with a normal hearing population.

Collaboration
There are many people necessary for teaching deaf students. General educators who have deaf children in their classrooms need the support of other professionals who need to work together as a team. They include social workers, rehabilitation counselors, speech and language teachers, interpreters, and audiologists.

Parents and relatives are also an important since they advocate for the child. When Chris was first diagnosed with a hearing problem, the doctors advised his parents to put him in an institution. The professionals offered no other options or treatment plan. Chris' parents would not easily give up on their son. They searched for an early intervention program in their city and began working with a teacher when Chris was aged three. To help parents and siblings, there are signing classes to communicate with the child.

In the community, there can be offices for the deaf. Theses offices maintain a list of qualified interpreters for hospitals, schools, courts, and police departments. The interpreters are given a standardized test to evaluate their expressive and receptive sign language skills. Text telephones may be provided by non-government organizations so that deaf people can communicate with others. Vibrating cell phones with message capabilities are also helpful. Captioned TV helps deaf to follow sports, news, political conventions, and press conferences help the deaf to be aware of the news around them.

Program Options
Parents are the key decision-makers in the child's life. They choose whether they will use sign language, speech, or both. They decide how early they will begin working with professionals. With so many decisions to make, parents often need help and medical and research centers can give advice. For example, if a family cannot afford a hearing aid, there may be an agency that donates them. One center begins working with parents and child when the child is two months old. Parents learn to socialize with their child and use the residual speech the child has. A center may also offer the help of a deaf person to explain that deaf people do grow up and can be content.

Question:
7. Where would you look for assistance in buying a hearing aid for a child?

 

 

In grade schools, along with speech and auditory therapy there are other aspects of life to be taught. Pre-teaching is used in one school where the children are coached before class about the concepts they will be learning. Students are also taught cognitively (problem solving and acquisition of basic concepts in math and science) and second, they give students practical examples to further explain the cognitive training. For example, the idea of "same" and "different" uses visual and actual objects to explain why some things are recognized as the same and others are different. Annual evaluations of the child each fall help the teaching staff to know if the child's language is at his developmental level.

Hopefully, in high school, there will be less assistance and greater independence for the deaf student. There are still supports of interpreters and speech therapists, but this time needs to be for academics. Schools try to provide two kinds of experiences - academic challenges and successes based on the deaf student's abilities. Secondly, they need opportunities to develop their own interests. This can be done through after school clubs and sports activities. For example, during Deaf Awareness Week, Chris organized activities for all the high school students to give them insight and information about communicating with deaf students. He also represented his class in the student government, planning for social events, and he attended photography and journalism classes, which prepared him for editing his school newspaper.

What Happened to Chris?
He went to college and got a job with a small company. He met a girl, married, and now has two children. He and his wife like to hike and travel. The struggles he and his parents overcame have been rewarded.

Much of this lecture was adapted from:
The Exceptional Child, Turnbull, Turnbull, Shank, and Leal, Prentice Hall, 1995.
http://www.agbell.org/information/brochures_have_win.cfm