Hearing Loss and Deafness
HEARING LOSS AND DEAFNESS
About 1 in 1,000 children demonstrates hearing loss to a level considered deaf or partially hearing and in need of special educational support. Severity of hearing loss may differ in one ear compared to the other and will vary greatly for different children.
Levels of Hearing Loss
Hearing loss is measured in decibels (dB) and is generally subdivided into three major groups. A loss greater than 55 dB is considered severe to moderate. Hearing loss is termed severe if it averages between 70 and 90 dB. Averaged across all frequencies, a hearing loss in the better ear of 90 dB or greater is considered profound. A child with mild loss of less than 40 dB may still be able to hear speech and have only moderate difficulties. With a loss between 40 and 55 dB some children can still hear some speech sounds, and these children may get a boost from a hearing aid.
In addition to the degree of hearing loss, the frequency range that is affected profoundly influences hearing ability. A child with mild hearing loss across the frequencies used for producing speech may have more difficulties. Speech will sound quite distorted and less intelligible for a child with 55 dB loss, who will hear more vowels than consonants, since vowels are transmitted at higher frequencies. A complete audiometric assessment of a child's hearing loss must, therefore, provide information for each ear, across a range of frequencies.
Additional problems suffered by hearing impaired children are: brain damaged (8%), cerebral palsy (7%), heart disorder (6%), perceptual-motor difficulties (10%), emotional and behavioral problems (19%), and visual deficits (18%)" (Harris 1990, p.208).
In the mid-1700s, Charles-Michel de l'Epée, a French cleric, observed that twin girls who had grown up together used fluent gestures to communicate with each other, and it occurred to him that this gestural language might already be equipped with syntax. He proposed to extend the native sign language of the deaf with supplementary methodical signs until this sign language became the intellectual equivalent of any spoken language. Today there are many sign languages based on hand signs and they differ widely in different countries and are not mutually intelligible for a deaf person. American Sign Language (AMSLAN or ASL) is a true language with syntactic and morphological rules different from those of spoken English. ASL signs are distinguished from one another by hand shape, movement, location in space, orientation of the hands during signing, and facial expression. In a book published in 1979, Edward Klima and Ursula Bellugi provided specific descriptions of ASL grammar and rules.
Some signing systems have added artificial signs for English morphemes such as verb tense markers and "is." Signed English, Seeing Essential English (SEE), and Cued Speech are a few of the manual forms developed. SEE was developed to represent spoken English literally, so that a signed sentence would be as complete as the spoken one. When the syntactic language skills of deaf children of deaf parents who used either ASL or SEE were analyzed, children in the SEE group achieved higher scores. The performance of the SEE children was closer to the English scores of hearing children. Nevertheless, some researchers, while observing teachers who employed a signed English system, found that many of the declarative statements and questions signed were grammatically incorrect. This may occur when teacher training is not rigorous and may also occur simply because of the increased number of signs required by SEE compared with ASL. Some specialists reason that it is not necessary to sign each and every morpheme of oral English, because a child can infer the missing elements from predictable structure and semantics, as well as through lipreading and use of residual hearing. A potential problem when SEE is used is that some children may not have the necessary reasoning and thinking skills to deduce from context the deleted segments of a manual message. Young children may be bombarded with too much information; they can misinterpret a message because of stress.
Deafness in Relation to Language and Social Development
Language deficits are the most serious consequence of hearing impairment. The effects of deafness on language development are complex. Hearing loss may vary across the range of frequencies. Children with severe or profound hearing loss generally have greater difficulty learning language. Children "who are born deaf, or who become deaf in the first year of life, have considerably more difficulty in developing language than do children whose deafness is acquired later in life" (Harris 1992, p. 96). Their opportunities as infants for turn-taking talk with significant caregivers are limited. Hearing parents use far fewer signs with them than the number of words used by hearing parents of hearing infants. Deaf toddlers of hearing parents cannot carry on extended conversations nor can they ask for clarifications, repetitions, or confirmations to repair frustrating communication breakdowns.
Whether a child has hearing or deaf parents is an important influence on the effect of hearing loss. Children born to deaf parents may be familiar with sign language from birth. Often on developmental tests they outperform their deaf peers born to hearing parents (about 95% of deaf children), who may experience sign language only when they go to school. Some studies show that deaf preschoolers lag about two years behind on language development tests, but they have similar categorization skills and similar scores on tests of nonverbal cognitive ability as their hearing peers.
The timing of diagnosis and intervention differs quite widely for infants born deaf, and this timing affects social and language development. Only about 10 percent of deaf infants are diagnosed in the first year, and accurate diagnosis may not occur until three years of age for up to 44 percent of deaf babies. Many children do not have a chance at early intervention because identifying hearing loss is not a regular part of an early detection system in infancy. Yet, current technology makes it possible in the earliest months of life to confirm that infants with normal hearing respond clearly to changes in phonemes, even when these phonemes are confounded later in their culture's language system (such as "l" and "r" in Japanese); for example, by about ten months of age, hearing Japanese infants no longer respond differently to the "l" and "r." Thus, early diagnosis of hearing can be accomplished and needs to become a mandatory procedure included in pediatric care for young infants. Legislation is beginning to mandate screening for hearing in newborns.
Social skills and intimate interactions of deaf children suffer when diagnosis is delayed. Adults may not be sensitive to orienting the infant to watch for facial expressions or to alert the child to visually relevant and interesting events. Peers in nursery school may shout at the deaf child who seems to be able to move about the playroom with ease to get a preferred toy, but who does not respond to invitations to play or to cues for assuming a role in a pretend play scenario. Sensitive teachers in inclusive preschool classrooms help deaf children so they, too, can participate in the world of imaginative play so typical of and so important for preschoolers. The deaf child without a friend in such a situation may shadow an adult teacher or act lonely and withdrawn. Teachers can actively encourage play group entry skills and teach all the children how to sustain sessions of play activity.
Training of early childhood educators should include ideas for activities and interactions that will increase chances for deaf children to be included in social play. In some inclusive classrooms, all the children learn some signs in order to communicate with children with hearing deficits. Finger plays and singing games that involve a lot of hand and body motions are one way to promote inclusion in play.
Reasons for language assessment vary and become particularly crucial if a child has reached school age and has difficulties with lessons. Tests for measuring receptive and expressive language in childhood depend mainly on a tester using oral language. Thus, even a receptive language test such as the Peabody Picture Vocabulary Test (PPVT), which requires only that a child listen to the examiner ("Show me bed") and then point to one of four pictured items on a page, depends on a child's hearing ability. The Grammatical Analysis of Elicited Language-Preschool Sentence Level (GAEL-P) (is a test that specifically analyzes the English skills of deaf and hard-of-hearing preschoolers. In the single-word vocabulary part of this test, children are asked to identify objects either by signs or by speech. Children are also asked to select objects that the tester names with signed and spoken words. The number of words the preschoolers produce and understand is a measure of their expressive and receptive vocabularies.
Testing requires decisions about why, how, and what tests to use. Marie Thompson and her colleagues suggested that reasons for assessment of deaf school-age children are: "To provide numerical scores to school districts; to identify a developmental language level and specific language targets for remediation; to measure efficacy of intervention based upon change in language behavior" (Thompson, Biro, Vethivelu, Pious, and Hatfield 1987, p. 30). These authors provide an extensive array of tests from which to choose when creating a custom-tailored battery of tests for a particular hearing-impaired school-age child.
Education of Deaf Children: Research Findings
The majority of deaf youngsters do not receive infant intervention and early exposure to ASL. When they do, the language patterns of children learning ASL from early infancy closely parallel the developmental progression of hearing children acquiring oral language. Infants learning ASL as a first language generally develop their first signed words at about the same age and sometimes even earlier than children learning an oral language. The two-word stage in ASL learning has some semantic features similar to the production of telegraphic speech among toddlers learning oral language. Overregularization of grammatical features ("I falled down") and overextension of word meanings (for example, calling all men "daddy") occur among toddlers whether they are using manual signs or oral speech.
Research suggests that knowing ASL early as a first language aids deaf children in developing better skills with the English language. Orally educated deaf children of hearing parents have been found to outperform manually educated children of hearing parents. This may mean that parental mastery of the language used in the earliest transactions with a child is most important for a young child's developing language skills.
Some drawbacks to education for deaf infants occur when hearing parents have not learned to use ASL or they use it infrequently and provide only simple signs. In addition, the variety of existing signing systems can be a serious source of frustration and inconsistency for children. Support for and educational opportunities for parents and caring family members to learn sign language should be an important goal of intervention programs for deaf infants.
Families and educators have differed historically in promoting different educational approaches to help deaf children develop language. Oralist programs emphasize that deaf children are best served by learning to read lips, by auditory training to use residual hearing as much as possible, and by articulation training to improve spoken enunciation.
Manual systems are urged by those who believe that some deaf children will have a poor educational prognosis with only oral methods. Use of manually coded English (such as finger spelling and ASL) in combination with speech is called total communication. Quigley and King provided an overview in 1982 of the half-dozen most commonly used sign systems.
Most of these systems share the common feature of adapting some ASL signs for vocabulary items. They invent new signs, for example, for plurals and as affixes for expressing verb tense and number agreement. ASL has fewer such elements. Reduplicated movement in ASL signals the progressive aspect, whereas some sign systems prefer to invent more movements to get closer to standard English, as in signing "The dog is barking" (in ASL this would be signed as "Dog bark, bark, bark").
Although sign systems are now an integral part of the curriculum for most deaf children, educational opportunities for the very young deaf child may be severely limited if a child is not participating in an educational program and if the parents themselves have limited knowledge of or use of sign systems.
Writing and Reading
Essays of deaf students frequently reveal patterns of ungrammatical English usage. Discrepancies that are similar to those of very young children developing normally include failure to invert subject and auxiliary when using a question, or omission of the verb "to be" (the copula) in a sentence. But deaf children often show other difficulties in mastering English syntax in their writing. For example, a ten-year-old wrote: "We perttey fun camp after home. The will week fun camp after car." An eighteen-year-old wrote: "A boy give to a dog eat the bread" (Quigley and King 1982, pp. 444-445).
Some of the distinct syntactic structures that deaf children generate involve a confusion between "have" and "be" ("Mama have sick") and an incorrect pairing of auxiliary with verb markers ("Mary has washing the dishes"). In using the passive voice, deaf children are likely to delete the word "by." They are also likely to delete conjunctions ("Eddie carried, dumped trash"). Question formation is difficult ("Who a girl bought you a doll?"). Relative pronouns may be deleted and substitutions made ("I patted the girl's arm was hurt").
In writing, deaf children's essays often overuse simple sentence structure. This may result from classroom drills to encourage the development of syntactic skills as well as spelling and punctuation rules. Reading materials, however, more commonly have advanced sentence structure; they require more mastery of complex sentences than are used in spoken conversations.
Effectiveness of Oral and Manual Educational Systems
Controversy still exists as to the relative effectiveness of oral and manual educational systems. Some intensive oral programs do report good English proficiency. Some total communication programs likewise report positive outcomes in English proficiency for their graduates. Studies suggest that the academic and social benefits of total communication are increased and sustained when total communication is used both in the school and in the home.
There is some agreement that the nature of the child's hearing loss and the degree of the child's cognitive ability may have a greater effect on successful educational outcome than other intervention program variables that are measured. At present, "un-equivocal statements about the value of particular approaches or the consequences of not following one approach or another are unwarranted" (Musselman, Lindsay, and Wilson 1988, p. 88).
Specialists agree that early interventions with deaf infants and young children must emphasize communication exchanges during activities. When adults exchange signs in play contexts (such as "peekaboo" and pretend driving a toy car on a track) and during daily routines, such as getting ready for bed or going shopping for a toy, then young deaf children begin to organize knowledge of events into mental representations and cognitive categories. The more generous the provision of such intimate and motivating interactions, the more a child has an opportunity to attempt to express cognitive structures in ASL or in oral language. Thus, organized, interpretable, and rich experiences within naturally occurring social routines are necessary for language development. Early interveners, often parents, need to provide abundant opportunities for signing. They need to maintain eye contact and show vigorous interest in the deaf baby's attempts to communicate gesturally. When the infant is playing with a toy, adults need to compose their hands in front of the baby and provide the sign for that toy. In contrast, toddlers will be delayed in learning signs if the parent takes a toy away first and waits for the child to look up and see the parent making the sign while holding the toy. Parents can receive much help from written materials.
Teachers need to seat a deaf child so there is good visibility. They must learn the optimal distance (under one foot) to stand when trying to communicate with a child using a hearing aid; and they must learn to change a hearing aid battery and/or cord. When a child with profound hearing loss wears two hearing aids connected to a cassette-player-like box suspended by straps at the waist, this apparatus is sometimes called a "phonic ear." Teachers may wear a microphone that amplifies their voice for a hearing-impaired child with poor lipreading and sign language skills.
Teachers need to use a child's name and articulate clearly and slowly when directing speech to a hearing-impaired child. They should kneel at a desk and focus on cuing. Cued speech, developed by Dr. Cornett at Gallaudet University in Washington, D.C., is a system of teacher hand cues that enhances lip-reading by children. The hand cues, used near the lips, match what is being said to clarify ambiguities. Cued speech used by a trained adult helps the hearing-impaired school-age child increase reading skills.
Multimedia technology has been used to develop materials and activities for Mexican-American deaf children, the fastest-growing minority group in the U.S. school-age population of deaf children. Video dictionaries of sign language can be built directly into stories onscreen. CD-ROM reading software is now becoming available for hearing-impaired children.
Teachers and parents working together create opportunities for deaf children so that they can use total language communication to achieve interpersonal goals. Enthusiasm and acceptance help hearing-impaired children experiment with their language systems so that they can learn well and have a positive social effect on others, as well as engage in peer friendships.
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