Educating Children with Visual and Hearing Impairments
Visual and Hearing Impairments
Special education teachers are charged with teaching a diverse group of learners. Some students come to the classroom with visual and or hearing impairments that impact not only the child’s developmental level, but his or her academic achievement. The educator must have a working knowledge of the types, degrees and causes of these impairments. Additionally, the teacher should be familiar with the legal definition and the definition as it relates to educational outcomes so that he or she can correctly select, plan and implement the Individualized Education Plan (IEP).
Humans are equipped to hear sounds by way of the intricate workings of the ear and the ability of the ears functional relationship with the brain. Heward (2010) describes the hearing process as the outer ear absorbs sound waves that travel through the tympanic membrane, more commonly known as the eardrum, transferring the energy of sound to the middle ear and entering the most complex part of the brain the cochlea. The cochlea is the main receptor organ for hearing and works with the semicircular canals which control our sense of balance (2010). The auditory nerve carries the sound as it has been transferred through this intricate system to the brain, where the information is process for response.
Understanding the multifaceted system is important when determining the impact of hearing on a person’s development and academic achievement. Hewitt (2010) claims, the ability to interpret sound is directly affects the ability to speak and the ability to speak direct affect the ability to read and write because these skills require “graphic representation of phonologically based language…The average deaf student who leaves high school at 18 or 19 is reading at about the fourth grade level” (p. 336). Daleabout, Martinez & Hallahan (2002) go on to claim that students with hearing loss are ten times more likely than typically hearing children to fail a grade.
The legal definition of hearing impairment according to US Legal (www. http://definitions.uslegal.com/h/hearing-impairment/) is “A hearing impairment is a full or partial decrease in the ability to detect or understand sounds. It can range from a mild hearing loss to total deafness”. While this is an accepted definition IDEA goes further in defining hearing impairments focusing on the educational implications involved. Hewett (2010, p.334) reports the IDEA definition as:
Deafness means a hearing impairment that is so severe that the child is impaired in processing linguistic information through hearing, with or without amplification, [and] that adversely affects a child’s educational performance (P. L. 108-446,20n U.S.C. 1401 , 20 D.F.R. 300.8[c]3])
Hearing impairment means impairment in hearing, whether permanent or fluctuating, that adversely affects a child’s education performance but that is not included under the definition of deafness in this section. (P.L. 108-446, 20 U.S.C. 1401 , 20 D.F.R. 300.8[c] ).
Although most educators consider children with hearing loss to be hard of hearing, there are two main types of hearing loss. Conductive, or those caused by abnormalities of the outer or inner ear and sensorineural hearing loss that refers to damage to the auditory nerves (Heward, 2010). A combination of both types is considered a mixed hearing loss while a hearing loss in one ear is termed a unilateral loss (2010). Causes of hearing loss are considered to be congenial which are due to genetic factors, maternal rubella, congenital cystomegalovirus and prematurity or acquired due to otitis media, meningitis, Meniere’s disease and noise induced hearing loss.
The impact of visual impairment can be enormous. Heward (2010) discusses motor abilities; including reaching for objects, learning to crawl, cruise and walk will be interrupted as the child may be fearful of getting hurt. Social and emotional interactions will be adversely impacted and will require substantial intervention.
Heward (2010) discusses that we see via three systems of the eye. The optical, muscular and nervous systems work together to take in visual information, move the eye to assist in “searching, tracking, converging and fixation on images” (p. 376) and finally the images are converted into electrical impulses and transmitted to the brain where it is processed and the person then can respond to what is seen. Damage to any one of these three systems will result in a visual impairment. Visual impairments are categorized into three broad categories. Refractive errors, myopia (nearsightedness) or hyperopia (farsightedness) are impairments of the eye, or the inability of the eye to focus light rays on the retina. Structural impairments such as cataracts, glaucoma, nystigmus and strabismus are caused by poor eye development, damage to the eye or a malfunction of one or more parts of the eye. Cortical Visual Impairments (CVI) is caused not by structural damage to the eye, but rather an interruption in how the brain interprets visual information. According to Roman, et. al. (2010), approximately 30-40% of children with visual impairments have CVI. Some of these children do not qualify for services as the condition is considered a processing disorder rather than a visual impairment (2010).
According to Heward (2010) a person is legally blind if his or her visual acuity is 20/200 or less in the better eye after correction with classes or contact lenses. Children who are legally blind will find it very difficult to attend to visual stimuli in the classroom without special assistance. A student with 20/70 eyesight is considered to be partially sighted, and if a person’s field of vision is extremely restricted such as with tunnel vision, he or she is also considered legally blind (2010). IDEA acknowledges the loss of vision as it relates to educational circumstances. Heward (2010) cites IDEA as: “visual impairment including blindness means impairment in vision that, even with correction, adversely affects a child’s educational performance. The term includes both partial sight and blindness. (20. U.S.C. 1401 . 20 C.F.R. 300.8 [c] )” (p. 373).
Understanding the impact of visual impairments and hearing impairments is crucial to those who endeavor to teach these special students. The teacher must have a clear understanding of the type, degree and cause of the impairment which will give him or her insight on the impact the impairment has on the student’s development and academic performance. Learning the structures of the eye and ear, and how the brain process visual and auditory information gives the teacher clues to how the student may access curriculum and which modifications would be most helpful. The teacher also must be keenly aware of the definitions as defined in IDEA in order to write appropriate and legal IEP’s.
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