FINAL

10.1 What Are Hearing Impairment, Deafness, Visual Impairment, Blindness, and Deaf-Blindness?

This section will outline the differences between hearing impairment and deafness, and between visual impairment and blindness. Students who experience comorbid difficulties with hearing and sight may be described as having deaf-blindness. Regardless of disability category, to be eligible for services under IDEA 2004, students must demonstrate adverse effects to their educational outcomes.

Defining Hearing Impairment and Deafness

An individual who has a decreased ability to hear sounds is said to have a hearing impairment. People born with this impairment are said to have a congenital hearing impairment, but individuals can develop a hearing impairment at any point in their life. They may experience hearing loss in one or both ears.

Noise levels are measured in units called decibels, which are electric signals that indicate the intensity of sound. The lower the decibel level, the quieter the sound. Individuals with typical hearing can hear sounds in the range of 0–25 decibels. Those with mild hearing impairment can hear 26–40 decibels; with moderate impairment, 41–70 decibels; with severe impairment, 71–90 decibels; and with profound impairment, only higher than 90 decibels. Someone who can hear only in the 71–90 decibel level needs sound to be much louder than the person with typical hearing requires. Students with mild and moderate impairments may have trouble hearing distant sounds or typical conversational voices. Students with severe or profound hearing impairment require assistive devices to hear any ordinary sounds.

Deafness is different from hearing impairment; it describes the condition of not hearing sounds even with assistive devices. Some people are profoundly deaf, which means that they cannot hear any sound at all. Others can hear some sound, but the sounds come through so quietly as to be indistinguishable.

The Deaf community differs from the deaf community, and people typically associate with one community or the other. Members of the deaf community see themselves as members of the hearing world, and do not identify primarily as deaf. These students usually attend regular schools. Members of the Deaf community, in contrast, relate strongly to Deaf culture and primarily associate with other Deaf individuals (Hamill & Stein, 2011). Students who are members of the Deaf community usually attend special schools for Deaf students. There is debate between the two parties and their advocates, especially since the advent of cochlear implants, about whether young children will be part of the deaf community or the Deaf community (Gale, 2011).

You may have noticed the term Deaf individuals in the previous paragraph, which clearly violates the person-first language discussed in Chapter 1 and used throughout this book. The Deaf community has rejected person-first language because members feel that it trivializes a person's Deaf identity. So, when referring to a person, a school, or a community of Deaf persons, it is more common to not use people-first language. A student in the deaf community, meanwhile, is typically referred to as "a student with a hearing impairment."

Hearing Impairment, Deafness, and IDEA

Hearing impairment and deafness have been two separate categories under IDEA since PL 94-142 in 1975. IDEA 2004 defines hearing impairment as: "an 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." Deafness, conversely, is defined in IDEA 2004 as a "hearing impairment so severe that the child is impaired in processing linguistic information through hearing, with or without amplification, such that his educational performance is adversely affected."

Students qualify under hearing impairment when they do not qualify under deafness. Most of the time, diagnosis of a hearing impairment or deafness is conducted outside of the school, and the school accepts the diagnosis. An IEP team then decides the best placement for the student.

Most students with hearing impairment participate in the general classroom with or without assistive devices (e.g., hearing aid or sound amplification system). Students may receive services from a specialist related to speech and language; they may also use a sign language interpreter. Other Deaf students may attend special programs or schools.

Defining Visual Impairment and Blindness

Visual impairment refers to a decreased ability to see that interferes with performance of daily activities. Students with visual impairment have some sight, but their sight difficulties may make it difficult to walk around, read, drive, or learn. Visual impairment can occur in one or both eyes. Individuals can be born with a visual impairment, or their vision can decrease because of injury, disease, or other conditions.

Blindness refers to a complete or almost complete lack of vision. However, if an individual is blind, it does not mean that he or she sees nothing. Many people who are blind may be able to see different colors, objects, and shapes.

Vision involves both visual acuity and the visual field. Visual acuity is the clarity and sharpness with which a person sees an object. In the United States, visual acuity is represented by two numbers (e.g., 20/20). People who have 20/20 vision can see the level of detail when they are 20 feet away from an eye chart (Figure 10.1) that others with normal vision can see at that distance. This "normal" vision has been determined over many years of examining human eyes. People who have 20/100 vision must be 20 feet away to see what a person with normal vision can see at 100 feet away. Visual field refers to an individual's line of sight above, below, to the left and right, and straight in front, when not moving the head. A person with normal vision usually has a visual field of about 190 degrees.

Figure 10.1: Snellen Eye Charts

The Snellen chart on the left is often used to test visual acuity. The chart on the right is used with younger students and others who cannot read letters but who can demonstrate which way the "fingers" of the E point with their own fingers.

Individuals with a visual impairment may have lower than normal visual acuity, a smaller visual field, or both. Their visual acuity is 20/70 or less in their better eye with corrective lenses. The visual field may be less than 20 degrees. To break down visual impairment further, the following terms are typically used. Low vision refers to vision from 20/70 to 20/160 with corrective lenses. People with low vision can usually see enough, often with technologic assistance, to participate in daily activities. Severe visual impairment includes people with vision from 20/200 to 20/400 when using corrective lenses.

Because a visual acuity of 20/200 or less refers to legal blindness, many people with a severe visual impairment may be diagnosed as legally blind. Legal blindness can also refer to a visual field of less than 20 degrees.

The National Federation for the Blind, the primary advocacy group in the United States for blind persons, prefers not to use person-first language. Thus, it is acceptable to say "the blind person." However, person-first language for students with visual impairment should be used (e.g., "a student with visual impairment").

Visual Impairment, Blindness, and IDEA

IDEA 2004 addresses both visual impairment and blindness under the single category of visual impairment. After the passage of PL 94-142, many students with visual impairment were placed in classrooms with sighted peers and teachers who did not have the proper training or resources to provide an effective education. Schools are getting better at providing appropriate educational services to these students, and schools and families may choose from a variety of placement options (Suvak, 2004).

Some students spend most of their time in the general classroom, with special education teachers or specialists pushing in to assist the student. Others may be placed in a self-contained classroom that supports the needs of students with visual impairment. Students with severe impairments may attend specialized schools, some of which are residential, that can provide specialized instruction.

Defining Deaf-Blindness

Deaf-blindness refers to difficulties related to both hearing and vision. Very few people with deaf-blindness cannot hear or see at all; most have varying degrees of hearing impairment and visual impairment.

Deaf-Blindness and IDEA

Deaf-blindness is its own disability category under IDEA 2004. Individuals in this category have "concomitant hearing and visual impairments, the combination of which causes such severe communication and other developmental and educational needs that they cannot be accommodated in special education programs solely for children with deafness or children with blindness."

For babies and toddlers with deaf-blindness, early intervention services are vital, especially in communication and speech (Dammeyer, 2010; McKenzie & Davidson, 2007). The IFSP guides the education of individuals with deaf-blindness until age 3. Once they enter school, most students with deaf-blindness receive most or all of their education in self-contained classrooms, special schools, or residential programs.

Prevalence of Hearing Impairment, Deafness, Visual Impairment, Blindness, and Deaf-Blindness

The prevalence of students with difficulties related to hearing and sight is quite low, making them "low incidence" disabilities. The percentage of students who are categorized as having hearing impairment or deafness under IDEA is approximately 0.1%, while approximately 0.04% of schoolage students are categorized as having a visual impairment. With less than 0.01% of school-age students having deaf-blindness, it is the least common of all disability categories.

10.2 How Have the Fields Related to Hearing and Sight Disabilities Evolved?

The history of disabilities related to hearing and sight is rich and varied. Because it was often easy to identify people as "blind" or "deaf," stories of people with hearing and sight difficulties appeared in writings, and people reached out to help those with difficulties communicate with the hearing and sighted world by developing their communication in different ways than the spoken or written word.

Evolution of the Hearing Impairment and Deafness Field

Deafness and hearing impairment have been recognized for centuries, if not millennia. Centuries ago, most people believed that deaf people could not learn because they could not hear, and people who were deaf were described as "dumb" or "mad." Some even said that children were born deaf because "God was angry" (Anglin-Jaffe, 2013).

The Greek philosopher Plato mentioned people using signs to communicate with the deaf around 400 BCE (Ruben, 2005). The first record of an attempt to teach a deaf child to speak was in 685 CE in England, where a teacher was able to teach the "Dumb Boy of Hexham" how to speak some sounds and a few words (Laes, 2011).

In the 16th century, a monk named Pedro Ponce de Leon (not the explorer), who became known as the "first teacher for the deaf," created a school for deaf students in Spain (Ruben, 2005). Among the first to believe that deaf students were capable of learning, Ponce de Leon taught children how to speak and write. He also taught students to use hand signs to represent letters of the alphabet. This practice was also used by monks who had taken a vow of silence.

A contemporary of Ponce de Leon in Italy was Giralamo (a.k.a. Geronimo) Cardano. He had a son who was deaf, and Cardano worked to teach his son how to read and write. He also taught his son how to use different gestures and signs to communicate with hearing people. Some of Cardono's ideas were published in 1620 in a book about teaching speech to the deaf by Juan Pablo Bonet. Bonet also included pictures on alphabetic hand signals that later influenced Spanish, French, and American Sign Language (ASL) (see the feature, "American Sign Language").

Thomas Hopkins Gallaudet opened the first school for the deaf in the United States with Laurent Clerc and Mason Cogswell in Hartford, Connecticut, in 1817 (Sayers & Gates, 2008). Mason's daughter, Alice, became deaf as a toddler, and Gallaudet wanted to create a school for children like her. The school is still open and is today called the American School for the Deaf. It focused on instruction in sign language, and Alice Cogswell was the school's first graduate.

In 1864, the first college for the deaf opened in Washington, DC (van Drenth, 2003). Edward Miner Gallaudet, Thomas' son, was the first president of the National College for the Deaf and Dumb. To recognize the Gallaudet family, this college was renamed Gallaudet College (and later Gallaudet University), and the university remains a leader in Deaf education.

In 1880, the National Association for the Deaf was founded as an advocacy group for people with hearing loss. During the late 1800s, there was quite a bit of controversy as to whether people should use sign language or learn to speak. While sign language would be easier than learning to speak a language that is difficult or impossible to hear, advocates for speech felt that learning to speak would allow people with hearing impairment to participate more easily in society. As the 20th century progressed, the choice to learn to speak or use sign language became the choice of the student or family. Today, ASL is the dominant form of communication for the Deaf.

Special Education: Your Profession

American Sign Language

American Sign Language (ASL) was developed from Old French Sign Language (OFSL), with homegrown signs that were developed in America (Figure 10.2). (OFSL was the sign language refined by Charles Michele l'Épée and brought to the United States by Laurent Clerc.) Many students who did not live near schools where they could receive formal sign language instruction created their own signs to communicate. This creation of signs also occurred in communities where a significant number of people in the population were deaf.

To use sign language, people use one or two hands to sign (or show) different letters, words, or phrases. Sometimes people touch or point to places on the face or head, or use facial expressions to show words or phrases. Some people who are deaf use their voices when they sign, while Deaf people will typically not use their voices at all.

Figure 10.2: American Sign Language Alphabet Chart

Each letter of the American alphabet has a unique hand gesture in ASL. People use these gestures to spell words. There are many additional gestures that signify commonly used words and phrases.

Because ASL is its own language, it has its own grammatical rules and word order. For example, to sign in ASL, "I have one brother," a person would make signs to represent "me, one brother." You may hear of Pidgin Signed English (PSE) or Signed English (SE). This uses ASL signs, but uses the word order of standardized English. Less important words (e.g., am, to, the) are not signed. A person would use PSE to sign, "I one brother." If students can speak, they may switch between ASL and spoken English (Andrews & Rusher, 2010), making them bilingual.

You may also hear of Signed Exact English (SEE). This is quite different from ASL. With SEE, a person signs using some components of ASL to represent English as it is spoken. It is the closest sign language to spoken English, and many speaking parents with children who are deaf may find it the easiest to use. In SEE, a person would make signs that say, "I have one brother."

ASL is used in the United States, most of Canada, and parts of Mexico. Many other countries have their own sign languages; for example, Italy and Spain each have sign languages much older than ASL. British Sign Language (BSL) is also very different from ASL. In fact, ASL and BSL only have about one-third of signs in common.

Students can learn ASL from a very early age. Many babies and toddlers use signs before they learn to speak (Brereton, 2010). The sooner students learn to use their hands to sign, the earlier they can communicate (Snoddon, 2008). Most students exposed to ASL learn to write in written English after they learn ASL (Enns, Hall, Isaac, & MacDonald, 2007).

Evolution of the Visual Impairment, Blindness, and Deaf-Blindness Field

Like those with hearing impairment, people with visual impairment or those who were blind were historically excluded from society. Some people who were blind were killed or abandoned. Blind men might be sold into slavery, whereas blind women might be sold as prostitutes. In the middle ages, societies began to feel more compassion for people with disabilities. "Poor houses" were set up to care for disadvantaged people, including the blind.

During the middle ages, magnifying glasses were created to help people with visual impairment see written text (Maldonado, 2001). Soon, two glass lenses were riveted together and worn on the bridge of the nose. In the 14th century, glasses were so fashionable that everyone wanted to wear them, whether they needed the corrective lenses or not. Johannes Gutenberg's invention of the printing press in 1440 and the proliferation of books created much more of a need for reading glasses.

In 1784, Valentin Haüy opened the first school for the blind in Paris, France (Lowenfeld, 1956). Haüy had seen a blind beggar named Francois Leseuer who could tell the value of coins by the raised markings on the coins. He decided to teach Leseuer to read, so Haüy created wooden blocks with raised letters and numbers. Because of his success educating Leseuer, Haüy decided to create books with raised letters. He opened his school, the Royal Institution for the Young Blind, and Leseuer was a teacher at the school (Oliphant, 2008). After the French Revolution, Haüy left France and moved to Russia. He opened a similar school in St. Petersburg, and other schools in England, Denmark, Austria, and Germany.

Following in Haüy's footsteps, Louis Braille invented a method for reading and writing that involved a series of raised dots. Blind from the age of 3, Braille attended the Royal Institution for Blind Youth in Paris, but had difficulty reading the raised letters. When he was 12, a soldier came to the Royal Institution with an invention called "night writing," which consisted of 12 raised dots that soldiers could use to share secret information during battle and at night without having to speak.

Around 1825, Braille took the idea of using dots and created his own system involving six dots to represent letters and numbers (Figure 10.3). He published his first book about his dot system when he was 20 years old. It took a while to catch on, and the Braille system of writing did not fully develop until the 20th century, but now it is used around the world to help people with visual impairment and blindness read (D'Andrea, 2009). With the invention of newer technologies, such as text-to-voice, Braille use has declined slightly, but it is still important in the blind community (Wall & Corn, 2004).

Figure 10.3: Braille

Braille printing arranges raised dots in a two-by-three grid to denote different letters, abbreviations, and punctuation. A person "reads" by moving a finger from left to right.

The first school for the blind in the United States opened in 1832 in Boston, Massachusetts. Originally named the New England Asylum for the Blind, the school is now called the Perkins School for the Blind, and it is a prominent school for blind education. Perkins is named after Thomas Handasyd Perkins, a visually impaired donor who gave money to begin the school. Samuel Gridley Howe became the director and raised funds to educate the blind. Howe brought Laura Bridgman, the first student with deaf-blindness to be educated in the United States, to the school. The Perkins Brailler, a Braille typewriter, was developed at the Perkins School (Bickford & Falco, 2012).

Anne Sullivan attended Perkins, and, upon graduation, was sent to Alabama to begin working with 7-year-old Helen Keller. Sullivan met Keller, who had become deaf-blind as a toddler, in 1887. Sullivan taught Keller how to communicate by drawing letters on Keller's hand. The next year, Keller traveled with Sullivan to Boston to attend Perkins. Sullivan and Keller worked together until Sullivan's death.

After Perkins was founded, other organizations for the blind arose in cities across the United States in the 19th century. The American Printing House for the Blind began in 1858 and printed books in Braille for blind students. In 1921, the American Foundation for the Blind (AFB) formed as an advocacy group for blind people. A similar organization, the National Federation for the Blind (NFB), started in 1940. The NFB worked to help the American public understand blind people as normal people who cannot see, instead of helpless beings.

One of the more important efforts of the NFB was the nationalization of the White Cane Law. The NFB wrote a model of the White Cane Law that states could adopt, and all 50 states have a version. Many people with visual impairment use a cane (usually white with a red tip, but it can be different colors) to help them navigate their environment. The White Cane Law basically states that blind people with canes or guide dogs have the same access rights as people without visual impairment. This allows blind people to take their canes and dogs into public buildings, restaurants, airports (and airplanes), buses and trains, and other public places. The White Cane Law also states that cars must stop when a person with a white cane is walking in a crosswalk.

10.3 What Are the Characteristics of Students With Hearing Impairment, Deafness, Visual Impairment, Blindness, and Deaf-Blindness?

Many babies and children have hearing or visual impairments that are not immediately apparent. This section discusses the characteristics of students with hearing and vision difficulties. Parents and guardians should be aware of these warning signs in order to refer children for early evaluation.

Hearing Impairment and Deafness Characteristics

Students with hearing impairments may experience hearing loss that is mild (i.e., student can hear sounds in the 26–40 decibel range), moderate (41–70 decibels), or severe (71–90 decibels). Students with deafness can only hear sounds above 90 decibels. Most students with hearing impairments fall within the mild and moderate categories, and it may not be obvious to parents or caregivers that the child is experiencing hearing difficulty.

Often signs of hearing impairment or deafness become apparent between birth and 12 months of age. Babies may not respond to voices. For example, if two adults are speaking, the baby may not turn his or her head in the direction of the voices. (Babies with typical hearing often look in the direction of noise.) Babies may not smile when someone is speaking to them, and babies may not respond to their own name.

Additionally, babies may not respond to loud noises in typical ways (turning in the direction of a loud noise or showing displeasure at it). For example, when a fire truck drives past with blaring sirens, most babies will start crying because the noise bothers their ears. If a baby is not frightened or does not seem to notice a very loud siren, the parent or guardian should bring the baby to a hearing assessment.

Because babies with hearing impairment are not hearing sounds well or at all, they are not picking up on some of the basics of language and communication. Often, babies and toddlers with a hearing impairment will not babble or make first sounds like "ba" and "ma." The single biggest indicator of hearing loss is delayed speech development.

Parents should have their child's hearing evaluated by a medical professional if they suspect hearing difficulties. As with many other disabilities, early intervention is vital because hearing is the foundation for developing speech and language skills.

Hearing loss may also occur at later ages. Toddlers and children may display delays in speech and language or they may have atypical speech patterns (e.g., speaking without inflection). Children may have difficulty engaging in conversation with other children or adults, and may seem to have difficulty understanding what others say. They may not respond when someone calls their name, or consistently turn the volume up high on televisions or audio systems. Some children experience earaches or ear pain; children may touch or cover their ears to indicate hearing difficulty. If a parent or teacher suspects that a student has a hearing impairment, the child should undergo an evaluation as soon as possible.

Visual Impairment and Blindness Characteristics

Students experience a range of vision difficulties, ranging from visual impairment, to low vision, to severe low vision, to blindness. Most students have sight difficulties, but not complete blindness: therefore, it may be difficult for parents and teachers to recognize a vision problem.

Several signs can indicate that a student has a visual impairment. Sometimes, the eyes themselves may be the first clue. Students may cross their eyes or not be able to focus on an object. They may squint or blink often, demonstrate sensitivity to bright lights, or close one eye often.

Other indicators can include clumsiness, as when a student regularly trips or runs into things or has trouble judging the distance to an object. For example, a student might swing a bat (to hit a ball) well before the ball crosses the plate. Students may choose to sit very close to a television or hold a toy or book very close to their eyes. The writing of students may be affected because they may experience poor hand-eye coordination.

Deaf-Blindness Characteristics

Students with deaf-blindness exhibit a combination of hearing and visual impairment characteristics. As noted earlier, it is important to remember that students with deaf-blindness usually have some sight and some hearing ability; it is extraordinarily rare that a student with deaf-blindness is completely deaf and completely blind.

10.4 What Are the Causes of Hearing Impairment, Deafness, Visual Impairment, Blindness, and Deaf-Blindness?

Hearing and visual impairments can come from a variety of causes. Congenital impairments are present at the time of a baby's birth. The impairment may be related to genetics or may stem from prenatal or perinatal causes. Acquired impairments occur after birth and are related to a disease, disorder, infection, or accident that happens to the student.

Causes of Hearing Impairment and Deafness

Hearing occurs when sound waves enter the auditory canal and hit the eardrum (Figure 10.4). The eardrum vibrates, and these vibrations travel through three small bones in the middle ear called the malleus (hammer), incus (anvil), and stapes (stirrups). These bones amplify the vibrations, and the amplification is picked up by very tiny hair-like cells in the cavity known as the cochlea. The hair-like cells move around, and the movements travel through auditory nerves to the brain. The brain interprets the messages as sound.

People can experience conductive hearing loss, which occurs when sound waves travel inefficiently to the eardrum and middle ear. Conductive hearing loss can often be improved with hearing aids. When a person has sensorineural hearing loss, the person has damage to the cochlea or the auditory nerves that send messages to the brain. Cochlear implants may help improve the hearing capability of a person with sensorineural hearing loss. When a person has damage to the eardrum and middle ear as well as the cochlea and inner ear, it is described as mixed hearing loss. People may experience hearing loss in one ear (unilateral) or both ears (bilateral).

Figure 10.4: The Ear

Some individuals experience hearing difficulty because of a breakdown in the process of sound waves traveling from the eardrum to the cochlea. Other individuals may have a disorder with the hair-like cells in the cochlea.

There are many causes for hearing impairment or deafness. A brief list includes the following:

Allergies. Many children suffer from allergies—and often, fluid can build up in the child's middle ear. Long-term build-up of fluid can contribute to hearing difficulty.

Chicken pox. The chicken pox virus can, in rare cases, cause an ear infection that leads to hearing loss.

Diabetes. Complications related to diabetes can cause infections that may lead to hearing difficulty.

Ear development. Students can be born with malformations of any of the parts of the ear that contribute to hearing impairment.

Ear infections. Eardrums can become infected, and without treatment, the infection can cause permanent hearing loss.

Earwax. If earwax collects in the ear canal, the wax can block sound waves from entering the inner ear. Earwax is typically related to temporary hearing difficulty.

Encephalitis. With encephalitis, parts of the brain may experience swelling. This swelling, if close to regions related to hearing, can cause hearing loss.

Genetics. Students may inherit a gene or genes that cause hearing loss. Interestingly, more than 90% of children with a congenital hearing impairment, or deafness, are born to hearing parents.

Head injury. Any injury that causes damage to the ear canal or the auditory nerves that carry messages to the brain may cause hearing loss.

Hypothyroidism. People with an underactive thyroid may experience hearing loss.

Lyme disease. The Lyme disease infection may affect the ear canal and cause hearing loss.

Meniere's disease. This disorder in the inner ear causes vertigo and can also cause fluctuating hearing loss.

Meningitis. With meningitis, especially bacterial or fungal meningitis, parts of the brain and spinal cord may swell. This swelling may affect the parts of the brain related to hearing.

Mumps. The mumps virus can cause an ear infection that leads to hearing loss.

Otosclerosis. In this hereditary disorder, the student has growths around the bones in the middle ear, which contribute to sound waves not travelling through the ear canal properly.

Ruptured eardrum. If a student is exposed to very loud noises, gets an ear infection, or has an accident where the eardrum is punctured, hearing loss can occur.

Sickle-cell anemia. Students with sickle-cell disease can also experience sensorineural hearing loss.

Syphilis. An infection related to syphilis may contribute to hearing loss (even years after the initial infection).

Tuberculosis (or the medicine used to treat it). While tuberculosis may not cause hearing loss, the medications used to treat it (e.g., streptomycin) may cause hearing loss.

Tumors. Tumors that grow in the ear or in locations of the brain related to auditory nerves can cause temporary or permanent hearing loss.

Causes of Visual Impairment and Blindness

The process of sight is complex, and abnormalities at any step can cause visual impairment (Figure 10.5). Light enters the eye through the cornea, a clear cover at the front of the eye, and then passes through the pupil, a hole in the center of the eye (surrounded by the iris) to the lens, which focuses the light rays onto one point on the retina. The retina is the back part of the eye that has cells that sense light. The visual information is then transmitted from the retina to the brain via the optic nerve, where it's interpreted as a visual image.

Figure 10.5: The Process of Vision

Light passes through the cornea, pupil, and lens to the retina, which helps interpret the light and then sends messages to the brain through the optic nerve. The brain interprets the messages as images. At any point, a defect in one of these parts of the eye or the optic nerve can contribute to difficulty with vision.

Visual impairment or blindness can be present at birth or develop during childhood. Disease, eye disorders, injury, or degenerative conditions can all lead to visual impairment. Examples of factors that can lead to visual impairment include:

Amblyopia (lazy eye). The eyes do not align properly, and one eye becomes weaker than the other. In a small child, the brain will shut down the vision in the weaker eye.

Cataracts. The lens of the eye becomes clouded, and light is prevented from passing through.

Coloboma. Part of the iris has a hole or a defect. Most coloboma is congenital.

Cortical visual impairment. When the part of the brain that carries messages about vision is defective, students can experience vision loss.

Diabetic retinopathy. The retina blood vessels become damaged, which leads to vision difficulty.

Genetics. Students inherit a gene or genes that cause vision loss.

Glaucoma. Pressure inside the eye damages the optic nerve. While glaucoma is typically thought of as affecting older people, glaucoma can affect children.

Infectious diseases. Diseases, such as measles, rubella, and scarlet fever, can cause infections that may contribute to visual impairment.

Macular degeneration. When part of the retina deteriorates, vision is impaired. Macular degeneration is one of the most common causes for visual impairment in older adults.

Nystagmus. An involuntary movement of the eyes that often develops between birth and 6 months of age. The movement causes vision difficulty.

Optic nerve hypoplasia (ONH). If the fibers in the optic nerve are underdeveloped in the womb, a baby may experience visual impairment related to this underdevelopment. Students with ONH often experience developmental delays.

Retinitis pigmentosa. A disease that slowly destroys the retina.

Retinopathy of prematurity. When babies are born premature, the retina does not have time to develop properly, which can lead to blindness.

Strabismus. When a person has difficulty aligning both eyes at the same time. Children with strabismus may appear cross-eyed.

Trachoma. This contagious bacteria causes an eye infection. Trachoma is the most common cause of blindness in the world, but it is extremely rare in the United States.

Vitamin A deficiency. When children do not receive enough Vitamin A in their diet, the deficiency can cause damage to the retina. Vitamin A deficiency is one of the most common causes for visual impairments in third-world countries.

Causes of Deaf-Blindness

Deaf-blindness, although extremely rare, can be caused by a number of reasons. Some of the most common include:

Asphyxia. When a person experiences a lack of oxygen, damage to the brain can occur, leading to hearing and vision loss. Babies can experiences asphyxia during birth if the mother experiences a drop in blood pressure or if the umbilical cord gets caught or wrapped around the baby.

CHARGE syndrome. CHARGE stands for coloboma, heart defect, atresia choanae, retarded growth and development, genital abnormality, and ear abnormality. Students with CHARGE syndrome experience a range of difficulties, and CHARGE syndrome is one of the leading causes for deaf-blindness.

Complications due to premature birth. Babies born prematurely may experience atypical development of the ear and eyes that leads to to hearing and vision loss.

Cytomegalovirus (CMV). CMV is a common herpes virus that can cause a delay in brain development to a baby in the womb.

Genetics. Children can inherit genes related to hearing and vision loss.

Hydrocephalus. When a child's brain collects excess fluid, the functions of the brain can be affected, leading to hearing and vision loss.

Infection or injury. Children can experience infections (e.g., measles, rubella, fevers) or injury to the head and brain that can contribute to hearing and vision difficulties.

Microcephaly. When a student's brain does not develop in a typical way, the brain is smaller than a typical brain. The brain function of a small brain is reduced, and this can cause difficulties with hearing and sight.

10.5 How Are Students Diagnosed With Hearing Impairment, Deafness, Visual Impairment, Blindness, and Deaf-Blindness?

Most often, parents recognize symptoms of hearing loss or vision loss and seek evaluation. Medical professionals may also identify children for evaluation at birth or during normal check-ups. Teachers may watch for signs of hearing or vision loss, especially after a student has experienced an illness or accident. Regardless of who notices warning signs, medical professionals conduct the evaluations and confirm a diagnosis. The school IEP team decides whether the student's hearing or visual impairment requires special education services because academic performance has been affected.

Diagnosis of Hearing Impairment and Deafness

Hospitals often administer a hearing test to babies before they leave the hospital. This usually begins with an otoacoustic emissions (OAE) test, which is administered when the baby is sleeping. A tiny device that makes clicking sounds is placed in a baby's ear. The device records the baby's echo response to the sounds—that is, whether sound waves come back out of the ear canal. If an echo is produced, then the baby's ear function is probably normal.

When a baby's OAE test results are abnormal, the automated auditory brainstem response (AABR) test is administered. Electrodes placed on the baby's head record brainwave activity in response to clicking sounds emitted from headphones. If the brain responds to the clicking sounds (i.e., the brain shows activation from hearing the sounds), then the baby's hearing is most likely normal. If brainwaves are not activated by clicking, then the baby might have a hearing impairment.

Parents and teachers who suspect hearing difficulties may refer toddlers and older children for a hearing screening. Many types of tests may be administered. A medical professional, such as an audiologist, may insert probes into the ear to determine how sound waves bounce off the eardrum (see the feature, "What Does an Audiologist Do?"). Another test, called an audiogram, determines the quietest sounds a child can hear. Children may also be tested for ear infections. Speech and language assessments may be administered to determine delays in basic skills.

Once a hearing impairment or deafness is identified, a team of professionals works with the family to determine the best treatment plan for the child. For many children, a hearing aid can help amplify sounds enough to improve the child's hearing substantially (Rekkedal, 2012). For other students with severe or profound hearing loss, a cochlear implant may be an option

Diagnosis of Visual Impairment and Blindness

Usually, a visual impairment is diagnosed by an ophthalmologist or optometrist. An ophthalmologist is a medical doctor (MD) specializing in eyes, and an optometrist is a doctor of optometry (OD) without a degree from a medical school. An optometrist understands and works with eyes, whereas an ophthalmologist can treat the entire body.

The first step in an examination is typically a vision test using a Snellen chart, shown earlier in this chapter. Doctors will also administer a visual field test. A set of goggles is placed on the patient, and lights flash on and off in the periphery of the visual field. The patient presses a button any time he or she sees a light.

Tests of the eye itself are also typically included in a vision evaluation. Doctors examine the cornea, pupil, iris, and lens to look for deterioration or damage. They may test to see if fluid pressure has built up in the eye. Doctors may also test how well signals in the optic nerve travel to the brain.

Beyond the basic evaluation, professionals (e.g., a visual impairments teacher or a certified orientation and mobility specialist) may conduct a functional vision assessment (FVA) for students with low vision. In an FVA, the student participates in near tasks (closer than 16 inches), intermediate tasks (16 inches to 3 feet), and distance tasks (over 3 feet). Tasks may include looking at pictures for specific objects or manipulating objects. The FVA helps teachers understand which accommodations (e.g., use of bold print, use of magnifying lens) may be necessary for the student in the classroom.

Diagnosis of Deaf-Blindness

To diagnose deaf-blindness, medical professionals use the same procedures as used to identify hearing impairment and visual impairment. Often deaf-blindness accompanies other medical conditions, so medical professionals conduct the evaluation for hearing and vision loss.

10.6 How Do I Teach Students With Hearing Impairment, Deafness, Visual Impairment, Blindness, and Deaf-Blindness?

An IEP team decides the most appropriate placement for each student, and the parents' wishes should be considered, along with the requirement of LRE. For example, some parents of Deaf children may opt for a classroom that uses ASL as the main form of communication instead of spoken English. For those students who spend some or all of their time in a general classroom, there are a number of accommodations, modifications, technologies, and organizational and instructional strategies that can make all the difference in educational outcomes. The effective introduction of specialists—such as a speech and language pathologist or an orientation and mobility specialist—can also improve academic performance.

Teaching Students With Hearing Impairment and Deafness

If students are placed in the general classroom, teachers can use a variety of accommodations and modifications to enable participation in the general classroom. Students may use interpreters if ASL is their primary form of communication and they attend their local schools. Other students attend schools where instruction is provided in ASL.

Many students with hearing impairment who use spoken English as their main communication method attend local schools. The inclusion of students with hearing impairment benefits all students, as students learn to be accepting of individual differences and communicate in unique ways (Bowen, 2008). No matter what the placement situation, students need qualified teachers who understand the needs of students with hearing impairment (Ausbrooks, Baker, & Daugaard, 2012).

Accommodations

For students with mild or moderate hearing loss, the classroom may have a sound-field amplification system (DiSarno, Schowalker, & Grassa, 2002). To use this system, the teacher wears a microphone, and wireless technology transmits the teacher's voice to an amplifier that typically is installed on a wall, on the ceiling, or in the front of the classroom. The entire classroom of students hears the teacher's voice through the amplifier.

All students seem to benefit from the amplification system, in terms of improving listening skills (DiSarno et al., 2002). Alternatively, the teacher may wear a microphone that wirelessly transmits the teacher's voice to the student's own hearing aid.

Students with hearing impairment often receive test accommodations in the form of extended time, small-group or individual administration, test directions interpreted, and test items interpreted (Cawthon, 2009). These accommodations may be in place for classroom assessments and standardized assessment programs implemented by the school or district. Some students may have tests translated into ASL. Depending upon the severity of disability, some students may take an alternate assessment (i.e., the modified assessment program for up to 2% of the school population).

General Teaching Strategies

Teachers of students who are deaf or hearing impaired should eliminate unnecessary directions and words to provide students with concise, clear information. For example, instead of saying, "For your art project, you'll gather a paintbrush and three colors. Choose blue, red, and yellow paints. Then, go to your easel and place your paint in the tray," a teacher might say, "Get a paintbrush and the colors blue, red, and yellow. Put the paint in the tray." Teachers should also check for understanding by asking students to repeat directions or explain a task that they are to perform.

It is helpful to allow "wait time" after asking a question before expecting a response. Often, students with hearing impairment need a little extra time to process information and produce an answer. Teachers may provide advance organizers (e.g., "Today we're learning about the difference between rectangles and squares") to help students prepare for the types of questions or activities that may be asked or covered in class.

Students with hearing impairment often fall behind their peers in terms of academics, so teachers may need to provide remediation to help catch students up to grade-level material. Students have often fallen behind because of inadequate language and speech skills. If students cannot understand the speech of the teacher, then they miss out on much of the instruction during the school day. Once a student's speech and language improves, teachers need to fill in any academic knowledge the student missed out on. Strategies for students with SLD can be beneficial to students with hearing impairment or deafness who need help in the academic areas.

Teaching Speech and Language Skills

Instruction on speech and language skills is based on the student's IEP. One challenging area for students with hearing impairment is vocabulary and new concepts. Often, students with hearing impairment learn concrete concepts well (e.g., car, truck, sun) but struggle with more abstract concepts (e.g., around, before, after). Pictures and videos are very helpful for demonstrating concepts that are language-based. If students are familiar with ASL, sign language pictures that accompany text may be used (Figure 10.6) (Hoffman & Wang, 2010).

Figure 10.6: ASL and Vocabulary

To help students who are comfortable with ASL learn important words or phrases, teachers can provide pictures of signs along with written text. In this example, the words to the Pledge of Allegiance are placed under the ASL signs.

Teachers also need to provide explicit instruction on homophones—words that sound the same but have different meanings (e.g., their, they're, there) and words that have multiple meanings (e.g., bark, can, play). Homophones, because they sound the same, can be very confusing to students who have limited language and vocabulary skills. Teachers may work on a pair of homophones with the student, providing examples of each one and when it can be used.

Students with hearing impairment often speak in shorter, more succinct sentences than other students. Thus, teachers may need to work with them on writing skills, such as developing and writing complex sentences (Massone & Baez, 2009). Teachers also need to help students learn to pay attention to word endings and plurals, as students with hearing impairment often have difficulty hearing these sounds. For example, a student may write, "I look for the cat," instead of "I looked for the cats."

Depending on how much sight and hearing students have, they may use Cued Speech, gestures, or lipreading. When using Cued Speech (Figure 10.7), students use their hands to signal different phonemes of English. Eight handshapes demonstrate consonant phonemes, and cues near the mouth demonstrate vowel phonemes. Cued Speech presents students with visuals of the spoken word. To use gestures, students communicate using informal signs. For example, a student may touch the mouth to indicate hunger. In order to lipread, students learn to understand speech by interpreting the movement and formation of the lips.

Figure 10.7: Cued Speech

To use Cued Speech, a person makes a handshape and then places the handshape in a specific location around the face to indicate a specific consonant, vowel, or consonant-vowel combination.

The Speech-Language Pathologist

Students with hearing impairment often miss out on critical communication and speech development. A speech-language pathologist (SLP) can help these students improve their communication skills. Students may receive these services at their school, travel to a clinic, or have the SLP come to their home.

The SLP helps students learn how to form and say sounds and words, speak, and listen. Many students with hearing impairment struggle with hearing quiet sounds, such as "s," "f," "k," and "t." SLPs may work with students on picking up on these sounds and using them in words. SLPs may also help students modulate the pitch of their voice and learn to speak at an acceptable volume rather than too loudly or too softly. Sometimes SLPs help students understand the connection between sign language and spoken English because sign language is not a direct interpretation of spoken English.

Teaching Students With Visual Impairment and Blindness

Some students with visual impairment or blindness—often those who have additional disabilities— attend specialized or residential schools. Specialized programs offer very specific resources for students (e.g., tactile maps, Braille readers, hallways with guide rails), and the teachers are specially trained to work with students with visual impairment. Many students, however, attend their neighborhood schools and participate in general classrooms for some or all of their day.

Classroom Organization

Teachers in a general education classroom can help visually impaired students navigate the classroom by following some basic rules. First, make sure the classroom is well organized and free of obstructions. Avoid clutter. Provide wide, clear aisles. Make sure no items hang from the ceiling or protrude from a wall in a place that a person could bump into. Once the classroom is set up, minimize changes. A blind student will learn quickly the pattern of desks and tables in the classroom. If they are rearranged, it can be very confusing.

Teachers should also think about the lighting in their classroom. For students with some sight, it is important for the space to be well lit. Schools can install better overhead lighting or teachers can use lamps placed around the classroom. Students may even have a desk lamp placed on their desk or work area.

Consider the placement of the student's work area in the classroom. Students with mild visual impairment might benefit from sitting in the front of the classroom, near the teacher, or close to the board area. Students who rely mostly on the spoken voice should be able to sit where they can easily hear the teacher and contribute to conversations. Teachers should stand facing the students as much as possible so that the students can use cues (such as hand gestures and facial expressions) as well as lip reading to understand the teacher.

General Teaching Strategies

Teachers need to provide explicit instruction for all the academic subjects. They should give thorough and concise directions and make sure that students understand expectations for each activity or assignment. By using explicit instruction and concise directions, teachers allow the student to focus on learning rather than be distracted by unnecessary information. Teachers may want to give out assignments or reading lists well before a due date, as students with visual impairment may need more time to read and digest information than a typical student.

Teachers should work on helping students with visual impairment improve their listening skills, since they rely heavily on listening to gather information and communicate (Durando, 2008). Listening skills can be improved with listening activities. A teacher may give students a list of things to do (e.g., items to gather from a locker) or tell a story and ask questions about the story. Teachers may also want to develop a verbal cue (e.g., "Time to listen") or a physical cue (e.g., hand raised in air) to signal students when it is very important to pay attention.

In the general classroom, placing students into cooperative learning groups benefits students with and without visual impairment (Najafi, Rostamy-Malkhalifeh, Pezeshki, & Amiripour, 2011). Students without visual impairment may act as helpers or guides, and the interactions may teach students acceptance of individual differences. Teachers should use assistive technologies when it would be beneficial for the student, as described later on (Zhou, Smith, Parker, & Griffin-Shirley, 2011).

For assignments and testing situations, some students with visual impairment may use a scribe, who writes out the work that the student dictates. The student can also use technologies, such as a computer or speech-to-text program, to type or transcribe work. Students may be provided with extra time for tests or untimed testing situations. As with all disabilities, accommodations on state assessments must be included in the student's IEP.

Teaching Reading and Writing Skills

Some students with visual impairment learn to read Braille—and sometimes sighted peers like learning it as well (Swenson & Cozart, 2010). Often, if students will use Braille as their main way to read, they learn it in a specialized school or program with a teacher experienced in teaching it. There are different grades of Braille, which are unrelated to school grades. At grade one, students read the letters of the alphabet using uncontracted Braille. At grade two, students read the letters of the alphabet and contractions (Barclay, Herlich, & Sacks, 2010). Most Braille used in public signs involves Contracted Braille. At grade three, Braille becomes a shorthand that is not standard English, in which dots represent words and phrases.

There is some debate as to whether students should learn uncontracted Braille before learning contracted Braille, or whether contracted can be learned first (Emerson, Holbrook, & D'Andrea, 2009). Whatever the orders of learning grades of Braille, however, students should learn Braille as they are learning to read (Holbrook, 2008; Swenson, 2008).

Students can also learn how to write in Braille, with a machine or by hand (Clark-Bischke & Stoner, 2009). Writing in Braille by hand involves using a device called a slate. A piece of paper is placed between two metal plates of the slate. The writer uses a stylus to form pits (that represent Braille) from right to left on the page. When the paper is taken out of the slate and turned over, the Braille can be read from left to right.

A focus on meaningful and important words in vocabulary instruction can lead to large gains in reading performance (Dimling, 2010; Campbell, 2011). For example, teachers can teach the meanings of the key words "journey" and "explore" to prepare students for a reading on the exploration of the Louisiana Purchase. Students with visual impairment often demonstrate difficulty with the basic parts of words, such as phonemes (i.e., smallest unit of sound), graphemes (i.e., the letters that represent phonemes), and onset rimes (i.e., in a one-syllable word, the initial consonant—onset—and the vowel and final consonants—rime), so teachers need to provide explicit instruction specific to these concepts (Crawford & Elliott, 2007).

Teachers should provide as many books as possible to students (Day, McDonnell, & O'Neill, 2008). Parental support of reading at home—whether in Braille or aloud—helps them learn to read unfamiliar words and greatly benefits their reading development (Kamei-Hannan & Sacks, 2012). Students may also use large-print books, which are available at many libraries.

Using Technology

Students may require that lectures or class discussions be audiorecorded. With technology—for instance, a digital recorder—this is quite easy to do. Students then may listen to the recording later to review or prepare for an exam.

Students may also listen to books or stories read aloud. Text-to-speech programs are readily available to translate written text to audible speech. Students can also speak and have their words translated to text with speech-to-text programs. There are many Braille translation programs available, and there is even a Braille tablet that students can use.

Some students may benefit from the use of large print. Using a computer, it is easy to change the font from a regular 12-point font to a 16- or 18-point font. With many e-readers, it is easy to enlarge the font to an appropriate size for individual students. Keep in mind, though, that for some students the large print may be distracting. The color contrast on most screens can also be improved (Figure 10.8).

Figure 10.8: Color Contrast

Many books, pictures, and websites on the computer do not present colored items in a way that is helpful for students with visual impairment. The color contrast at the top of the screen makes the text much easier to read than that on the bottom of the screen. Teachers may need to alter materials, using technology, to provide better contrast for students.

Tactile Learning

Whenever possible, teachers should provide students with tactile learning experiences so students can experience (with their hands) something that is difficult to see (with their vision). In teaching mathematics, technology can be used to create tactile images of important concepts, such as grids, geometric shapes, charts, and graphs (Bouck & Meyer, 2012; McDonnall, Cavenaugh, & Giesen, 2010).

In teaching social studies, a teacher may provide a raised map that the student can touch and feel to better understand geographical boundaries or characteristics, such as mountains and rivers. Teachers may provide 3-D models of objects, such as a space shuttle or a giraffe, so students can understand what these items look like (Smothers, 2011).

Arts and Physical Education

Students with visual impairment can learn to read music (via a Braille system) and play instruments (Coates, 2010). Music, whether played by the students or provided via recordings, is a great way to teach students new skills and concepts (Villasenor & Vargas-Colon, 2012). For example, students can learn the U.S. presidents by song. Students can also use music to help them focus and eliminate other background distractions. Students with visual impairment have to rely on listening, so nature sounds or classical music can help eliminate aural distractions and create a calm work environment.

Art experiences are an important component of education for these students, especially because of the tactile and expressive experiences art can provide. Students, even if they cannot see their art well, can use art to express themselves or answer questions. Students can use art to practice writing letters or words in print or Braille.

Students with visual impairment often have difficulty understanding spatial concepts. For example, when learning about the solar system, it may be difficult to understand the Earth's relation to the sun without seeing it. Using textured paint, a teacher can paint the different planets on a long piece of paper, and then the student can compare the distance between the sun and Earth or the Earth and Jupiter.

Students can also work on developing positive peer interactions and social skills in physical education classes (Conroy, 2012). By playing games or participating in activities with other peers, all students can learn acceptance of individual differences and how to not be afraid of students with disabilities. Physical education teachers can include students with visual impairments by providing verbal descriptions of activities alongside their physical demonstrations. Instead of saying, "Throw the ball through here," teachers might say, "Throw the ball through the hoop on the wall." Physical education teachers may also use devices that produce beeps or other sounds to make the basketball hoop, or other items, easier for students with visual impairments to locate.

Orientation and Mobility Training

Students with visual impairment benefit greatly from instruction on tasks that develop mobility and orientation. An orientation and mobility (O&M) specialist works with students in special schools or in general classrooms. In fact, over half of all students with visual impairment in any setting work with an O&M specialist (Wolffe & Kelly, 2011).

An O&M specialist helps students with visual impairment learn to independently navigate their environment in a safe way (Correa-Torres & Durando, 2011). O&M specialists usually work one-on-one with students. They might teach students how to navigate with a cane, or they might help a student learn how to travel with a guide dog. An O&M specialist teaches students how to ride the train or bus, how to cross the street, and how to enter or exit buildings. They might also help students with developing gross- and fine-motor skills, such as cutting with a knife and fork.

Teaching Students With Deaf-Blindness

All the teaching strategies for students with hearing impairment and students with visual impairment are applicable to students with deaf-blindness. Some students require highly specialized instruction (Correa-Torres, 2008), whereas others can attend their local schools and participate in inclusion programs (Kamenopoulou, 2012). General education teachers, if teaching a student with deaf-blindness, should receive proper training from their school district for working with these students (Hartmann, 2012). This training may include learning about evidence-based techniques for hearing and visual impairments, as well as any specialized care the student may require (e.g., wheelchair access).

People with deaf-blindness communicate in many ways. To use the hand-over-hand method of tactile sign language, the person receiving the signs lightly places his or her hands over the signer's hands. The signer then uses some version of sign language, such as ASL, sometimes modifying the signs so that they can be felt rather than seen. Other people use fingerspelling, in which one person spells letters on the other's palm. (This is the method Anne Sullivan used with Helen Keller.) Another method is Braille signing; one person points to places on the other's palm that represent the dots of Braille.

Helping Students With Visual and Hearing Impairments Transition

Transition plans to independent living must begin as early as possible for students with visual impairment. Students who are going to live on their own need to learn how to navigate their community with public transportation, how to grocery shop and prepare meals, how to interview for jobs or apply to college, and how to take care of their finances and personal care. Students may also require instruction on sexual relationships (Krupa & Esmail, 2010). They may need to continue to work on their communication and literacy skills, and teachers will want to keep them updated on recent technologies.

Secondary students with deaf-blindness should have transition plans developed early. Some students may need to learn a vocational skill to succeed after school (Parker, Davidson, & Banda, 2007). For example, students may work bagging groceries or cleaning stores. Other students may work in greenhouses watering plants. Students need to learn the skills related to their vocations in addition to daily living skills.

References

Powell, S. R., & Driver, M. K. (2013). Working with exceptional students: An introduction to special education [Electronic version]. Retrieved from https://content.ashford.edu/