Introduction
There are three major parts to the ear: outer ear, middle ear and inner ear. The outer ear is the part we see, including the ear canal. The middle ear includes the eardrum, which is technically called the tympanic membrane. It also includes the three bones or ossicles of the middle ear and the eustachian tube. The eustachian tube leads to the throat and helps equalize pressure in the middle ear. The inner ear includes the cochlea, which looks like a snail shell, and the semi-circular canals. Inside the cochlea are sensory cells which look like fine hairs and respond to sound then send nerve signals to the brain. The semi-circular canals help us maintain our balance.
There are three main types of peripheral hearing loss:
Conductive hearing loss occurs when the structures of the outer or middle ear don't work correctly. Some causes of conductive hearing loss are wax impactions in the ear canal, a ruptured ear drum, infectious fluid in the middle ear and disorders of the ossicles, such as otosclerosis. This type of hearing loss is more likely to respond to medical or surgical treatment.
Sensorineural hearing loss is linked to problems of the inner ear structures, and is sometimes called "nerve deafness." Some causes of sensorineural hearing loss are noise exposure, heredity and aging. In most cases, sensorineural hearing loss is permanent and is treated with hearing aids or in some cases, cochlear implants.
Mixed hearing loss occurs when someone experiences both types of hearing loss.
Who is Deaf and Hard of Hearing?
There are many different degrees of hearing loss. A mild hearing loss may mean that you have difficulty hearing and understanding someone who is speaking from a distance or has a soft voice. Understanding people speaking when there is a lot of background noise may be difficult.
If you have moderate hearing loss, you may have trouble understanding conversational levels of speech even if there is not any background noise. Hearing conversations with a noisy background is very difficult.
A severe hearing loss means you have trouble hearing in all situations. You may hear speech only if the speaker is talking loudly or is standing very close to you.
A person with profound hearing loss may not hear even loud speech or environmental sounds. Hearing may not be used as the primary means of communicating.
It's hard to estimate how many people in the United States are deaf or hard of hearing, because there is no legal definition of deafness as there is for blindness. The statistics available are from people who reported themselves as deaf or hard of hearing.
There are 30.8 million adults in the United States with hearing loss ranging from mild to severe according to the 2002 National Center for Health Statistics. The Better Hearing Institute reports that three in every 1,000 infants are born with serious to profound hearing loss. A little more than one million school-age children are deaf or hard of hearing. They believe hearing loss is under-reported, so their estimates are higher than those reported by the National Center for Health Statistics. And according to the National Association of the Deaf there are between 250,000 and 500,000 American Sign Language users in the United States and Canada. Hearing loss is a likely result of growing older: one out of three Americans over age 60 has experienced some loss of hearing. This is a special population with very different needs and concerns.
Research also pointed out some interesting facts: People 65 and older are eight times more likely to have hearing problems than people aged 18-34. White males are more likely than females to be deaf or hard of hearing. Whites are more than twice as likely as blacks to have hearing problems, and non-Hispanics are also more likely to have hearing problems than Hispanics.
The Better Hearing Institute believes that 90-95 percent of hearing loss can be corrected. Between five and ten percent of those people can be helped with medical or surgical options, including cochlear implants. The remainder can address their hearing loss through the use of hearing aids. While hearing aids cannot totally restore hearing, they can help improve hearing loss for many people.
A medical doctor who treats people with suspected hearing loss is an otologist or an otolaryngologist. The professional who specializes in evaluating hearing loss, conducting hearing tests and fitting hearing aids is an audiologist.
Causes of Hearing Loss
Many times there is no easy answer to the question of what caused a particular person to become deaf or hard of hearing. Hearing loss can occur because of heredity, illness, accident or aging. About half the time, genetic factors are the most likely cause of deafness. However, most deaf parents have hearing babies; deafness is not commonly passed on from parent to child. Well over 90 percent of deaf and hearing impaired newborns are born to hearing parents.
In the remaining cases of hearing loss where a cause is identified, environmental factors are responsible. These include accidents, constant high noise levels and illness. A child can lose its hearing before birth if the mother has rubella or another viral infection. During the actual birth process, factors like a loss in the oxygen supply can affect hearing. Premature babies can have hearing loss in addition to other conditions. Illness or infection in young children can affect hearing as well.
Exposure to explosive sounds, tumors, injury to the skull or ear, tumors or a combination of these factors can cause hearing loss. Some medications may specifically harm the ear. A congenital brain abnormality, tumor or lesion of the central nervous system can also cause hearing loss. High noise levels that are constant can cause progressive and eventually severe hearing loss, and this is a growing concern, especially for young people.
The National Center for Health Statistics of the U.S. Department of Health and Services estimates that three out of four people with hearing loss began to have trouble hearing after age 18. Only 5 percent reported onset before they could speak, or before three years of age.
About a third of the 19 million deaf and hard of hearing adults in the U.S. report that their loss is due to some sort of noise. Twenty-eight percent say their hearing loss is due to age, and 17.1 percent report that it is due to infection or injury. A small number -- 4.4 percent-- report the hearing loss as beginning at birth.
The Center for Assessment and Demographic Studies, in their annual survey of hearing impaired children and youth, estimate that heredity is the leading known cause of hearing impairment at birth. It accounts for 13 percent of hearing loss reported at birth. One out of every 2,000 children born will inherit hearing problems. Genetic deafness is less likely to be accompanied by other health problems.
Pregnancy/birth complications account for 8.7 percent of hearing loss reported at birth. This includes Rh incompatibility, prematurity, and birth trauma. When it results in a lack of oxygen and cerebral hemorrhage, premature birth can cause damage to the nervous system and subsequent hearing loss. When there is a blood type incompatibility between mother and child, some children will be born with a hearing loss and others will be born with cerebral palsy.
The most common cause of hearing loss in children is otitis media, or ear infection. According to the National Institute on Deafness and other Communication Disorders, otitis media is the major reason why young children are taken to the emergency room or the physician's office and the most frequent reason doctors prescribe antibiotic therapy for children.
Another cause of hearing loss after birth is bacterial meningitis. Boys are more likely than girls to contract this disease. Children under four are most susceptible to the disease, which is an inflammation of the lining of the brain. Most children are vaccinated against one type of meningitis, Hib, but there are other strains which are equally dangerous.
In the past, several factors caused deafness in children and adults. Between 1963-1965, a rubella epidemic swept through the country. Pregnant women who contracted rubella often had babies with hearing impairments, visual problems and heart defects. Now, pregnant women are much less likely to contract rubella, so the incidence of deafness due to this complication of pregnancy is greatly reduced.
Early Intervention and Educational Needs
Researchers are discovering more evidence every day about the importance of early intervention. In a recent study reported in the American Annals of the Deaf, researchers Kathryn Hoberg Arehart and Christine Yoshinaga-Itano estimate that approximately 16,000 babies will be diagnosed with hearing loss every year once universal newborn hearing screening is adopted.
Identifying the hearing loss at the earliest possible age is critical. If appropriate intervention begins by the time the baby is six months old, language development can be normal, no matter how severe the hearing loss. As healthcare professionals recognize this fact, there is a trend toward identifying hearing loss earlier, and children with hearing loss have a better chance of entering the educational system earlier and with language skills closer to those of their hearing peers.
The acquisition of language is the largest obstacle facing young students who are deaf and hard of hearing. Success in virtually every endeavor requires communication skills. Those skills suffer from the inability to hear and understand speech, unless the child is surrounded from birth by an alternate form of communication such as sign language.
There are many different opinions about the best educational approach for children who are deaf. Some parents and educators believe it is better to educate a child who is deaf in the same school system as hearing children, using special education teachers and resources. Others, including the National Association of the Deaf, maintain that “inclusion” must include a continuum of educational options based on a comprehensive assessment of each child and should include residential and other education choices.
In a residential school, students who are deaf are surrounded by other people just like them, and sign language is usually the dominant form of communication. Children who are deaf are not isolated from their classmates by a language barrier, and their self-esteem benefits from deaf role models in the classroom. Whether a child attends a residential school or not, it is crucial that the family members learn some form of communication so the child who is deaf can be included as part of the family group.
Amplification
Many people who are hard of hearing use amplification devices or hearing aids. The technology of hearing aids has made remarkable advances over the past quarter-century.
The most notable changes are changes in signal processing and size. A hearing aid in the 1960s amplified noise and conversation equally, so in a noisy situation, it was rarely helpful. The sound quality was somewhat like the sound of a cheap transistor radio --tinny and unnatural.
Twenty years later, signal processing had advanced to the stage where hearing aids at least did not make a noisy situation worse, and they were a great deal of help amplifying conversation in a quiet atmosphere.
Now, some hearing aids sample sound 50 times per second and have the ability to make loud sounds soft and soft sounds louder. Some hearing aids can produce fidelity as good if not better than expensive stereo systems. They come with different technological choices and different choices in size and placement.
In the 1800s, people who were deaf and hard of hearing used a variety of non-electrical trumpets and horns to amplify sounds. They worked basically as a kind of megaphone in reverse.
Alexander Graham Bell was working on a hearing aid when he invented the telephone. That technology was applied to hearing aids, but they were still very large and cumbersome. In the 1940s, vacuum tubes brought the size down some, but it took the invention of transistors in the 1960s for hearing aids to shrink down to the sizes in use today. Now, hearing aids can be worn above the ear, in the outer ear or even tucked away completely in the ear canal.
Assistive Devices
Hearing people may take their ability to hear for granted, but for people who are deaf and hard of hearing, life requires some adaptations.
One of the most widespread assistive devices is the TTY or TDD, telecommunications device for the deaf. It hooks up to a telephone and has a keyboard and a small screen across its face. The user dials a number and lays the receiver inside the TDD. The person on the other end of the line types text which scrolls across the screen of the TDD. The user can type his or her response, and the conversation continues. If the person being called does not have a TDD, most states have a relay service. The relay service operator types the messages to the person who is deaf and speaks to the hearing person. People without a TDD can call the relay operator to make a TDD call, too. Visit the Alabama Relay Service for additional information.
Just in recent years, video relay service has developed as a natural and easy alternative to the typing method of the TDD – the video relay system. An inexpensive video camera, like those commonly found on computers, is used to videotape the person using sign language. An operator/interpreter receives the video then translates the sign language into spoken language for the second party. The relay operator then translates the spoken English into sign language for the caller. No typing is needed. The person who is deaf needs to have a web camera and a computer, or a videophone and television. The person receiving a video relay call does not need any special equipment. Most AIDB Regional Centers are equipped for making video relay calls.
Due to the 1996 amendment to the Hearing Aid Compatibility Act of 1988, all voice telephones manufactured within or imported to the United States, including corded and cordless phones, must now have a volume control. Corded and cordless specialty phones in many cases can provide even more amplification than add-on amplifiers. These types of phones not only provide additional amplification, but may also provide other special accessibility features (e.g., tone controls, ringer controls, audio output jacks) along with standard telephone features (e.g., memory buttons for speed dialing, built-in answering machine)
In today’s world of pocket PCs and cell phone technology, many deaf and hard of hearing individuals enjoy the use of a Blackberry or Sidekick device to communicate in a more personal and timely manner. Email and the internet have also bridged many communication gaps in both the deaf and hearing worlds.
A device called a Visual Ring signaler can be hooked up to the telephone and a lamp, which will blink when the telephone rings. A similar device can be connected to the doorbell, or to a baby monitor to alert parents when a baby is crying. Another device might shake the bed when it's time to get up, instead of ringing an audible alarm.
Cochlear implants may be a choice for some people who are deaf. This system requires surgery to implant a device which is then connected to a receiver outside the ear. Unlike a hearing aid, they do not amplify sound. A device with a microphone and a speech processor is worn behind the ear or on the body. Sounds and speech are converted from acoustic energy to electrical energy. These electrical impulses are transmitted across the scalp to a device surgically implanted just beneath the scalp in the skull above the ear. This electrical energy is then sent to an electrode inserted into the inner ear and wrapped around the hearing nerve. When the hearing nerve is stimulated, electrical energy is then transmitted to the brain where it is processed and given meaning. A cochlear implant can allow someone to hear sounds at normal levels. The ability to be able to process and understand speech and language is dependent upon the recipient’s age at the onset hearing loss, how soon they received their implant and the development of the speech reception centers of the brain.
Instant messaging, closed captioning, speech recognition software and many new daily technology developments help people with hearing loss communicate.
Communication
People who are deaf or hard of hearing have many different communication options. There is often heated debate about which options are best. Practically every method is represented on the internet; see our "links" section or use any major search engine to find out more about the communication option which interests you.
American Sign Language (ASL) is a manual language distinct from spoken English. It has its own syntax and grammar, and is the second most common language in the United States. It has a fascinating history, beginning in France in the late 1700s, and brought to the U.S. in 1815 by Thomas Hopkins Gallaudet and Laurent Clerc. ASL is used as an expressive language, and written English is used to communicate with the hearing world. This communication method is also referred to asASL/ESL or bilingual/bicultural.
Many people who are deaf regard ASL as their natural language, reflecting their cultural values and keeping their traditions and heritage alive. ASL should not be confused with Signed English or the use of the manual alphabet to spell out each spoken word. Many states, now including Alabama, accept ASL as a foreign language requirement for high school students.
Interested in taking sign language classes? Find the Regional Center nearest you for information on local classes.
Auditory-Verbal or unisensory is a program which emphasizes auditory skills. Children are taught to develop listening skills through individual therapy focusing on using any remaining or residual hearing with the help of amplification. Because this method is designed to encourage a child's listening ability, no manual communication is used and the child is discouraged from using any visual cues.
Cued Speech is a visual communication system using eight hand shapes or cues to represent different sounds of speech. The cues are used while talking to make spoken language clear to the person who is deaf or hard of hearing. The cues help the listener distinguish between sounds that look the same on the lips.
Oral/Auditory Oral is a program that teaches people to maximize the use of their residual hearing though amplification by the use of hearing aids, cochlear implants, or an FM system. It also stresses the use of speech reading to help communication. Any sign language use is discouraged although natural gestures may be used.
Total Communication is a philosophy emphasizing the use of any and all methods of communicating. Students may be exposed to signed English, finger spelling, natural gestures, speech reading, body language, oral speech and amplification devices. The goal is to communicate and teach vocabulary and language by any practical method.
Finding an Interpreter
Sign Language Interpreters in Alabama are required to have a license or permit. Some interpreters specialize in a particular field, like medical interpreting or legal interpreting. Interpreters also must follow a code of ethics. For example, they must keep the information they learn while interpreting strictly confidential.
Businesses such as banks, car dealerships, doctors, attorneys and others are required by the Americans with Disabilities Act (ADA) to provide an interpreter for their customers who are deaf. Interpreters are needed in legal situations. Healthcare professionals like doctors and counselors must have an interpreter available so they can communicate freely with their patients. Schools, also, are required to have interpreters for their students so students don't fall behind in their class work.
The entire state of Alabama is experiencing a severe shortage of sign language interpreters. Some Regional Centers have an interpreter coordinator on staff who can help you find an interpreter. For more information on interpreter services visit our Regional Centers.
Culture
When a group of people come together to form a community, it is usually because they have shared experiences, common interests and shared rules for behavior. All these elements together are part of what makes up that group's culture. People who are deaf and share a language -- American Sign Language (ASL) -- often associate with others who use that language, and the group has formed its own unique culture. It is characterized by pride in an ability to overcome adversity and may emphasize political activism, social and emotional support.
There are hundreds of clubs and organizations of people who are deaf. Their goals may be as simple as getting together to socialize or as complex as changing the world to be more accepting of people who are deaf.
Deaf culture is highlighted by a fierce sense of pride in a hard-won ability to overcome adversity, both as individuals and as a group. This sense of pride became apparent to the wider world in 1988 at Gallaudet University, when students refused to accept a hearing president as leader of their Deaf university.
Like any culture, Deaf culture is too complex to be adequately explained in a short article. Some aspects which are valued in Deaf culture; however, are fluency in ASL and the ability to tell stories well. It is likely that a member of the American Deaf community will marry another member of that community, and many people who are Deaf wish to pass on their heritage and culture, including their values to future generations. There is a very strong sense of group loyalty.
It would be impossible for a hearing person to ever fully become a member of the Deaf community. On Cindy Dawes' homepage about ASL and Deaf culture, Carol Paden points out that even with deaf parents and fluency in ASL, the hearing person would have missed the experience of growing up deaf.
Residential schools become a critical link in the transmission of Deaf culture. All the children can communicate with each other easily, and participate in activities that may be denied them in public schools. Even more important, they are exposed to deaf role models. For the first time in their lives, deaf children may learn that the lack of hearing does not mean that they can't grow up to be successful and happy.
Within Deaf culture, to be deaf does not mean that you are disabled. It is, instead, a different way of being. Not all people who are deaf support the beliefs of Deaf culture, however. Every D/deaf person is unique and may have different opinions. People who are hard of hearing may or may not prefer Deaf culture over hearing culture.
Anyone who comes into any contact with people who are deaf learns to appreciate the sensitivity of the issues presented here. The loss of hearing has always been presented as a pathology, a negative outcome of disease. Deaf culture turns that assumption on its ear, so to speak, and compels all of us to take another look at preconceived notions of what is healthy and what is not.
Signs of Hearing Loss In Adults
For adults, look for these signs of hearing loss:
- shouting in conversation
- turning television or radio too loud for other family members
- continually asking others to repeat themselves
- withdrawing from social contact
- straining to hear
- misunderstanding conversations
- favoring one ear
- complaining of a ringing or buzzing in the ear
Signs of Hearing Loss in Children
- not responding when someone speaks to them
- saying "what" or "huh" frequently or asking for things to be repeated
- intently watching the face of the person speaking
- sitting close to the television with the volume high or turning up the volume on the stereo (this may be normal behavior for teenagers, though!)
- switching ears frequently on the telephone
- not being startled by loud sounds
- responding inconsistently to conversations -- sometimes hears what's been said and sometimes does not.
- a history of ear infections -- often getting earaches or runny ears
- complains of hurting ears
- prefers low pitched or high pitched sounds
- talks in a soft or loud voice
- confuses sounds that are alike
- speech is less developed than expected for age or child does not use verbal language at all
- answers questions with unrelated answers
- seems inattentive at home or school
Normal Hearing and Language Development
In infants and toddlers, look for these signs of normal hearing and language development. If they are lacking, consult your pediatrician immediately.
- startles, blinks eyes or other response to sudden, loud sounds (birth to 3 or 4 months)
- stops moving or stops crying when called or when hears unfamiliar noise (birth to 3 or 4 months)
- disturbed by loud sounds during sleep (3 months)
- soothed by mother's voice or shows response (3 months)
- imitates gurgling or cooing noises and responds to noise making toys (3 months)
- begins to turn eyes and head to the side in search of source of unfamiliar sound (4-5 months)
- turns head directly toward the sound of a signal, but cannot locate sounds from above or below (6-7 months)
- responds to everyday sounds such as running water, spoon rattling in cup or footsteps from behind (7-9 months)
- responds to sound of name (7-9 months)
- plug your ears! Baby should engage in loud shrieking and sustained production of vowel sounds (9 months)
- uses his or her voice to get attention (9-12 months)
- imitates sounds and simple words (12 months)
We hope you'll take the time to learn more about AIDB. We invite you to make use of our resources to learn more about the history, culture and experiences of people who are deaf.
Selected Sources (See "Links" for more information about deafness)
American Annals of the Deaf, 1999. Current and back issues are available at http://gupress.gallaudet.edu/annals/current.htm
Beginnings Homepage. An internet resource available at http://www.beginningssvcs.com/ (last accessed on January 9, 2000).
Berke, Jamie. "About.com Guide to Deafness/Hard of Hearing." An internet resource available at http://deafness.about.com (last accessed on January 5, 2000).
Better Hearing Institute. An internet resource available at http://www.betterhearing.org/ (last accessed on January 8, 1999).
The Boys Town Research Registry for Hereditary Hearing Loss. An internet resource available at http://www.boystown.org (last accessed on October 5, 1999).
Cindy's Homepage. An internet resource available at http://www.aslinfo.com (last accessed on October 5, 1999).
National Information Center on Deafness. An internet resource available at http://www.nih.gov/nidcd/ (last updated January 11, 2000).
Mayo Clinic Health Oasis . An internet resource available at http://www.mayohealth.org (last updated January 12, 2000).
Kulman, Linda. "What'd You Say?" April 26, 1999. Archived at the U.S. News website available at http://www.usnews.com.