Hearing, Hearing Testing, Hearing Aids, Hearing Conservation And Services

Transcription

1 Hearing, Hearing Testing, Hearing Aids, Hearing Conservation And Services is retained in all printings. 1

2 is retained in all printings. 2

3 Table of Contents Terminology... 4 How We Hear... 5 Causes of Hearing Loss... 6 Hearing Loss at Birth (Congenital Hearing Loss)... 6 Hearing Loss after Birth (Acquired Hearing Loss)... 7 Ear Infections (Otitis Media)... 7 Noise... 8 Ototoxic Medications (Medication Effects)... 8 Signs of a Hearing Loss... 9 Types of Hearing Loss... 9 Degrees of Hearing Loss The Audiogram Audiogram of Familiar Sounds Hearing Amplification Hearing Conservation Effects of Hearing Loss on Development Specific Effects Vocabulary Sentence Structure Speaking Academic Achievement Social Functioning What You Can Do Hearing Assessment Centres Schools for the Deaf Citations: Much content from Citations: Many images from is retained in all printings. 3

4 Terminology Hearing Loss - Hearing Loss occurs when a person does not hear sounds at the normal levels of hearing. With children, it is especially important to diagnose and treat a hearing loss as early as possible. This limits its potential impact on learning and development. Hearing loss can greatly affect the quality of life for adults as well. Unmanaged hearing loss can have an impact on employment, education, and general well-being. Hearing is measured in decibels hearing level (dbhl). Varying degrees of hearing loss Mild Moderate Severe Profound Hard-of-Hearing - persons who have a mild to moderately severe hearing loss are referred to as hard-of-hearing (partially hearing). deaf persons are said to be deaf if they have a severe to profound hearing loss. Deaf refers to a member of the Deaf community and an active participant in Deaf culture. Deaf persons use Sign Language as their main means of communication. Dumb and mute are NOT terms that are used is retained in all printings. 4

5 How we hear Figure 1. The ear can be divided into three parts leading up to the brain the outer ear, middle ear and the inner ear. The outer ear consists of the ear canal and eardrum. Sound travels down the ear canal, striking the eardrum and causing it to move or vibrate. The middle ear is a space behind the eardrum that contains three small bones called ossicles. This chain of tiny bones is connected to the eardrum at one end and to an opening to the inner ear at the other end. Vibrations from the eardrum cause the ossicles to vibrate which, in turn, creates movement of the fluid in the inner ear. Movement of the fluid in the inner ear, or cochlea, causes changes in tiny structures called hair cells. This movement of the hair cells sends electric signals from the inner ear up the auditory nerve (also known as the hearing nerve) to the brain. The brain then interprets these electrical signals as sound. is retained in all printings. 5

6 Causes of Hearing Loss Hearing Loss at Birth (Congenital Hearing Loss) The term congenital hearing loss means the hearing loss is present at birth. Congenital hearing loss can be caused by genetic or non-genetic factors. Non-genetic factors can account for about 25% of congenital hearing loss. Non-genetic factors that are known to cause congenital hearing loss include: Maternal infections, such as rubella (German measles), cytomegalovirus, or herpes simplex virus Prematurity Low birth weight Birth injuries Toxins including drugs and alcohol consumed by the mother during pregnancy Complications associated with the Rh factor in the blood/jaundice Maternal diabetes Toxemia during pregnancy Lack of oxygen (anoxia) Genetic factors (hereditary) are thought to cause more than 50% of all hearing loss. Hearing loss from genetic defects can be present at birth or develop later on in life. Most genetic hearing loss can be described as autosomal recessive or autosomal dominant. Other, more rare types of genetic hearing loss include X-linked (related to the sex chromosome) or mitochondrial inheritance patterns. In autosomal recessive hearing loss, both parents carry the recessive gene and pass it along to the child. Parents are often surprised to discover their child has a hearing loss because they are not aware that they are carrying a defective gene. This type of inheritance pattern accounts for about 70% of all genetic hearing loss. An autosomal dominant hearing loss occurs when an abnormal gene from one parent is able to cause hearing loss even though the matching gene from the other parent is normal. The parent who is carrying the dominant gene may also have hearing loss as well as other signs and symptoms that make up a genetic syndrome. The autosomal dominant pattern accounts for 15% of all genetic hearing loss cases. Genetic syndromes have a group of signs and symptoms that together indicate a specific disease. There are many genetic syndromes that include hearing loss as one of the symptoms. Examples include: Down syndrome Usher syndrome Treacher Collins syndrome Waardenburg syndrome is retained in all printings. 6

7 Hearing Loss after Birth (Acquired Hearing Loss) Acquired hearing loss is a hearing loss that appears after birth. The hearing loss can occur at any time in one's life, as a result of an illness or injury. The following are examples of conditions that can cause acquired hearing loss in children: Ear infections (very common in children) Medications that are toxic to the ear Meningitis Measles Encephalitis Chicken pox Flu Mumps Head injury Noise exposure Ear Infections (Otitis Media) Ear infections happen when the middle ear becomes inflamed. They can happen in one or both ears. Ear infections are among the most common sicknesses during childhood and can be painful. Many children will have at least one acute ear infection by the time they turn 1 year old. Ear infections are so common in children because the passage between the middle ear and the back of the throat is smaller and more horizontal in children than in adults. This allows it to be more easily blocked by infections in the ear. Sometimes children get fluid in their middle ear but do not have an infection. This is called otitis media with fluid. You may also hear or see the term "otitis media with effusion" or "fluid in the middle ear." A small number of children will have three or more cases of otitis media with fluid by age 3. Sometimes the cases can take a month or longer to heal. Constant ear fluid is more common in children under 2 years of age, but it can be seen in children older than 2. When fluid is present in the ear for a prolonged period of time, this can pose a risk of hearing loss. Hearing loss at a young age can affect typical speech and language development. Fluid in the middle ear makes it harder for your child to hear sounds because of conductive hearing loss. Imagine if you were trying to hear something underwater. That is what it might sound like to your child. is retained in all printings. 7

8 Noise Loud noise can be very damaging to hearing. Both the level of noise and the length of time you listen to the noise can put you at risk for noise-induced hearing loss. Noise levels are measured in decibels, or db for short. The higher the decibel level, the louder the noise. Sounds that are louder than 85 db can cause permanent hearing loss. The hearing system can be injured not only by a loud blast or explosion but also by prolonged exposure to high noise levels. How can I tell if I am listening to dangerous noise levels? You must raise your voice to be heard. You cannot hear someone 3 feet away from you. Speech around you sounds muffled or dull after you leave the noisy area. You have pain or ringing in your ears (this is called tinnitus ) after exposure to noise. Ototoxic Medications (Medication Effects) Certain medications can damage the ear, resulting in hearing loss, ringing in the ear, or balance disorders. These drugs are considered ototoxic. There are more than 200 known ototoxic medications (prescription and over-the-counter) on the market today. These include medicines used to treat serious infections, cancer, and heart disease. Hearing and balance problems caused by these drugs can sometimes be reversed when the drug therapy is discontinued. Sometimes, however, the damage is permanent. When a decision is made to treat a serious illness or medical condition with an ototoxic drug, your health care team will consider the effects of the medications on your hearing and balance systems. The team will discuss with you how these side effects will affect your quality of life. Ototoxic medications cause damage to the sensory cells used in hearing and balance. These sensory cells are located in the inner ear. There are more than 200 medications and chemicals that are known to cause hearing and balance problems. It is important to discuss with your doctor the potential for hearing or balance damage of any drug you are taking. Sometimes there is little choice. Treatment with a particular medication may provide the best hope for curing a life-threatening disease or stopping a life-threatening infection. Ototoxic medications known to cause permanent damage include certain aminoglycoside antibiotics, such as gentamicin (family history may increase susceptibility), and cancer chemotherapy drugs, such as cisplatin and carboplatin. Drugs known to cause temporary damage include salicylate pain relievers (aspirin, used for pain relief and to treat heart conditions), quinine (to treat malaria), and loop diuretics (to treat certain heart and kidney conditions). In some instances, exposure to loud noise while taking certain drugs will increase their damaging effects. is retained in all printings. 8

9 Signs of a Hearing Loss Signs vary with age. Watch for warning signs, such as: Newborn - is not quieted by Mom s voice 8-12 Months does not imitate human voice 18 Months cannot identify body parts when prompted 2 yrs cannot repeat phrases/follow simple commands 3 yrs cannot understand and use words like go, me, in 4 yrs cannot carry out 2 simple directions in a row 5 yrs cannot carry out simple conversation and speech is hard to understand School Age (6 yrs and over): Frequent colds and ear-aches Frequent inattentiveness Lack of concentration Below-par performance Leaning to one side to hear better Frequently asking speakers to repeat what was said Types of Hearing Loss Conductive hearing loss - Loss originates from the outer to middle ear, usually temporary and can usually be treated medically Sensorineural hearing loss Loss originates from the inner ear, permanent hearing loss Mixed hearing loss has conductive and sensorineural components is retained in all printings. 9

10 Degrees of Hearing Loss Degree of hearing loss refers to the severity of the loss. The table below shows one of the more commonly used classification systems. The numbers are representative of the patient's hearing loss range in decibels (db HL). The Audiogram dbhl dB 26 40dB 41 55dB 56 70dB 71 90dB 90+dB Hearing Level Normal hearing Borderline normal Mild loss Moderate loss Moderate to Severe Severe loss Profound loss Figure 2. Audiogram displaying degrees of hearing loss. The audiogram is a graph that shows your thresholds for the sounds that were used to test your hearing. A threshold is the softest level of the sound that you can hear. Across the top of the audiogram are the frequencies (pitches) that were tested, low frequencies towards the left and high frequencies toward the right. The frequencies that are tested represent the range of sounds that we have to be able to hear for everyday living. Down the left side of the audiogram are the sound intensities (in decibels, db), soft sounds at the top and loud sounds at the bottom. The lower the mark on the audiogram, the louder it has to be for you to hear it. The audiogram can be divided into regions that show how much hearing loss you have. Mild Hearing Loss causes difficulty understanding speech especially in difficult listening situations (soft speaker, noisy room, distant from speaker). People with mild hearing loss can usually understand conversation in a quiet room if they are near the speaker. Some people with mild hearing loss are helped by hearing aids. Others get by without hearing aids. Moderate Hearing Loss causes difficulty understanding speech in all normal conversations. Most people with moderate hearing loss get significant benefit from hearing aids. is retained in all printings. 10

11 People with Severe Hearing Loss cannot hear normal conversational speech at all. Most people with severe hearing loss benefit from hearing aids but many have difficulty understanding even with properly fitted hearing aids. People with Profound Hearing Loss cannot hear speech. They are usually not able to understand speech with hearing aids. Hearing aids are helpful for awareness of environmental sounds like traffic noise, alarms, and loud speech. Audiogram of Familiar Sounds Figure 3. This figure is displaying where typical sounds lie on an audiogram. The shaded area is known as a speech banana and shows where normal conversational speech sounds appear on an audiogram. A hearing loss below the speech banana (moderate to profound) will result in difficulty hearing normal conversational speech. is retained in all printings. 11

12 Hearing Amplification Most persons with a hearing loss can be helped with a hearing aid. Hearing aids differ in design, size, amount of amplification, ease of handling, volume control, and availability of special features. However, they do have similar components that include the following: Microphone to pick up sound Amplifier circuitry to make the sound louder Receiver (miniature loudspeaker) to deliver the amplified sound into the ear A battery to power the electronic parts Some hearing aids also have earmolds (earpieces) to direct the flow of sound into the ear and enhance sound quality. In the case of children, the earmold will need to be replaced fairly often as the ear grows. If you have hearing loss in both ears, the audiologist may recommend that you use two hearing aids. Wearing two hearing aids: Helps in localizing the direction of sounds Improves listening in noisy situations Provides better overall hearing The best hearing aid for you depends on your listening needs, type of hearing loss, and lifestyle. Your audiologist will advise you on which of the basic hearing aid styles and features best meet your needs and their related costs. a) b) Figure 4. Behind-The-Ear (BTE) hearing aid, a) with open fit design, b) with ear mold a) b) Figure 5. In-The-Ear (ITE) hearing aid is retained in all printings. 12

13 a) b) Figure 6. In-The-Canal (ITC) hearing aid a) b) Figure 7. Completely-In the-canal (CIC) hearing aid a) b) Figure 8. Invisible-In the-canal (IIC) hearing aid Citation: Photos from is retained in all printings. 13

14 Hearing Conservation Loud noise causes hearing loss by destroying the hair cells in the inner ear. People who are exposed to loud sound on a regular basis are most at risk. Sources of frequent loud noise exposures include noisy workplaces (factories etc.), recreational noise (motorcycles etc.), and loud music. Sometimes the hearing loss may be greater for some frequencies than for others. High-frequency hearing loss is a very common pattern with noise-induced hearing loss. Hearing may be normal for low frequencies with a mild, moderate, severe or profound loss for high frequencies. How can I protect my own or my child s hearing from loud noise? The key words are education and prevention! Dealing with noise and its effects on your hearing is a personal responsibility. The obvious first rule is to avoid loud noise whenever possible. A good rule of thumb is to remember that if you must shout to be heard, then you should avoid the situation. Here are some things you can do: Wear hearing protection. Cotton in the ears will not work. Hearing protection, such as earmuffs or earplugs, can be purchased at drugstores, hardware stores, or sports stores. Custom earmolds can be made to fit your ears by an audiologist. Learn how to correctly insert the earplugs and earmolds for the best noise reduction. Earplugs are placed into the ear canal so that they totally block the canal. They come in different shapes and sizes, or they can be custom-made by taking an impression of the ear. Earplugs can reduce noise by 15 to 30 decibels (db) depending on how they are made and fit. Earmuffs fit completely over both ears. They must fit tightly so that sound is blocked from entering the ears. Like earplugs, muffs can reduce noise 15 to 30 db depending on how they are made and fit. Earplugs and earmuffs can be used together to achieve even greater sound reduction. Use of earplugs and earmuffs is recommended when noise exposure is particularly high. Do not listen to loud sounds for too long. If you do not have hearing protection, move away from the loud sound. Give your ears a break from the sound. Plug your ears with your fingers as emergency vehicles pass on the road. Lower the loudness of the sound. Keep personal listening devices set to no more than half volume. Do not be afraid to ask others to turn down the sounds from speakers. Speak to the movie theater projectionist if the movie sound track is too loud. Be a good consumer. Look for noise ratings on appliances, sporting equipment, power tools, and hair dryers. Purchase quieter products. This is especially important when purchasing toys for children. is retained in all printings. 14

15 Be a local advocate. Some movie theaters, health clubs, dance clubs, bars, and amusement centers are very noisy. Speak to managers and those in charge about the loud noise and the potential damages to hearing. Ask to have the noise source lowered. Can my ears get used to noise? Do not be fooled by thinking your ears are tough or that you have the ability to tune it out! Noise-induced hearing loss is usually gradual and painless but, unfortunately, permanent. Once destroyed, the hearing nerve and its sensory nerve cells do not repair. If you think you have gotten used to the noise you routinely encounter, you may already have some hearing damage. Effects of Hearing Loss on Development It is well recognized that hearing is critical to speech and language development, communication, and learning. Children with listening difficulties due to hearing loss or auditory processing problems continue to be an under identified and underserved population. The earlier hearing loss occurs in a child's life, the more serious the effects on the child's development. Similarly, the earlier the problem is identified and intervention begun, the less serious the ultimate impact. There are four major ways in which hearing loss affects children: 1. It causes delay in the development of receptive and expressive communication skills (speech and language). 2. The language deficit causes learning problems that result in reduced academic achievement. 3. Communication difficulties often lead to social isolation and poor self-concept. 4. It may have an impact on vocational choices. is retained in all printings. 15

16 Specific Effects Vocabulary Vocabulary develops more slowly in children who have hearing loss. Children with hearing loss learn concrete words like cat, jump, five, and red more easily than abstract words like before, after, equal to, and jealous. They also have difficulty with function words like the, an, are, and a. The gap between the vocabulary of children with normal hearing and those with hearing loss widens with age. Children with hearing loss do not catch up without intervention. Children with hearing loss have difficulty understanding words with multiple meanings. For example, bank can mean the edge of a stream or a place where we put money. Sentence Structure Speaking Children with hearing loss comprehend and produce shorter and simpler sentences than children with normal hearing. Children with hearing loss often have difficulty understanding and writing complex sentences, such as those with relative clauses ("The teacher whom I have for math was sick today.") or passive voice ("The ball was thrown by Mary.") Children with hearing loss often cannot hear word endings such as -s or -ed. This leads to misunderstandings and misuse of verb tense, pluralization, nonagreement of subject and verb, and possessives. Children with hearing loss often cannot hear quiet speech sounds such as "s," "sh," "f," "t," and "k" and therefore do not include them in their speech. Thus, speech may be difficult to understand. Children with hearing loss may not hear their own voices when they speak. They may speak too loudly or not loud enough. They may have a speaking pitch that is too high. They may sound like they are mumbling because of poor stress, poor inflection, or poor rate of speaking. Academic Achievement Children with hearing loss have difficulty with all areas of academic achievement, especially reading and mathematical concepts. Children with mild to moderate hearing losses, on average, achieve one to four grade levels lower than their peers with normal hearing, unless appropriate management occurs. Children with severe to profound hearing loss usually achieve skills no higher than the third- or fourth-grade level, unless appropriate educational intervention occurs early. The gap in academic achievement between children with normal hearing and those with hearing loss usually widens as they progress through school. The level of achievement is related to parental involvement and the quantity, quality, and timing of the support services children receive. is retained in all printings. 16

17 Social Functioning Children with severe to profound hearing losses often report feeling isolated, without friends, and unhappy in school, particularly when their socialization with other children with hearing loss is limited. These social problems appear to be more frequent in children with a mild or moderate hearing loss than in those with a severe to profound loss. What You Can Do Recent research indicates that children identified with a hearing loss who begin services early may be able to develop language (spoken and/or signed) on par with their hearing peers. If a hearing loss is detected in your child, early family-centred intervention is recommended to promote language (speech and/or signed depending on family choices) and cognitive development. An audiologist, as part of an interdisciplinary team of professionals, will evaluate your child and suggest the most appropriate audiological intervention program. Citation: Some content from is retained in all printings. 17

18 Hearing Assessment Centres KINGSTON Jamaica Association for the Deaf 9 Marescaux Road (Entrance on Caledonia Lane) Kingston 5 Phone: / / Fax: (fax) hearingservices@jamdeaf.org.jm Dr. G. Beavers, AuD Caribbean Hearing Centre 18 Lindsay Crescent Kingston 10 Phone: / Fax: Dr. A. Thwin Saydanar Ear Care Unit 15a, 4 Seymour Park 2 Seymour Avenue Kingston 6 Phone: / Otolaryngology Centre 5 Tangerine Place Kingston 10 Phone: / ENT Clinic University Hospital of the West Indies Mona, St. Andrew (Tuesdays and Thursdays) MONTEGO BAY Dr. G. Beavers, AuD c/o ENT Mt. Salem Main Road (Across from Cornwall Regional Hospital) Montego Bay, St. James Phone: Dr. A. Thwin Eye, Ear, Nose & Throat Centre Shop # 43 Montego Freeport Shopping Centre Montego Bay, St. James Phone: MANDEVILLE Dr. G. Beavers, AuD c/o Dr. Auden s Office Hargreaves Hospital Mandeville Phone: (every 3rd Monday) Dr. M. Edwards, ENT 16 Caledonia Road Mandeville Phone: / is retained in all printings. 18

19 Schools for the Deaf KINGSTON & ST. ANDREW JAD Pre-School Centre Hope Estate, Papine, Kingston 6 Phone Number: Ms. Sharon Andrews sandrews@jamdeaf.org.jm jadpreschool@jamdeaf.org.jm Danny Williams School for the Deaf (JAD) Hope Estate, Papine, Kingston 6 Phone Number: Ms. Maureen Simmonds msimmonds@jamdeaf.org.jm dannywilliamsschool@jamdeaf.org.jm Exed Unit Class (JAD) 5 Courtney Avenue, Kingston 3 Phone Number: Ms. Dawn Williams dwilliams@jamdeaf.org.jm exedunit@jamdeaf.org.jm Lister Mair/Gilby High School (JAD) Hope Estate, Papine, Kingston 6 Phone Number: Mrs. V. Souza-McKenzie vsouzamckenzie@jamdeaf.org.jm listermairgilby@jamdeaf.org.jm listermair@yahoo.com Caribbean Christian Centre for the Deaf (CCCD) 4 Cassia Park Road, Kingston 10 Phone Number: / / Ms Maria Lawrence deaflink_cccd2@hotmail.com ST. ANN St. Christopher s School for the Deaf (JAD) St. Christopher s Crescent, Brown s Town, St. Ann Phone Number: Mrs. Milburn Simpson msimpson@jamdeaf.org.jm stchristophersschool@jamdeaf.org.jm st.christ@cwjamaica.com is retained in all printings. 19

20 CLARENDON May Pen Unit for the Deaf (JAD) Woodside District, Denbigh PO, Clarendon Phone Number: Mrs. Winsome Rhoden PORTLAND Port Antonio Unit for the Deaf (JAD) Williamsfield, Draper s District, Port Antonio, Portland Phone Number: Mrs. Avarine Smallhorn asmallhorne@jamdeaf.org.jm portantoniounit@jamdeaf.org.jm ST. ELIZABETH Maranatha School for the Deaf Top Hill, St. Elizabeth Phone Numbers: / / Ms. Precious Kennedy maranathasfd@yahoo.com MANCHESTER Caribbean Christian Centre for the Deaf (CCCD) P.O. Box 14, Knockpatrick, Mandeville Phone Number: Mrs. Icilda Demarcardo cccdkp_jm@yahoo.com / caricred@cwjamaica.com ST. JAMES Jamaica Christian School for the Deaf (JCSD) Physical Address: Eden District, Montego Bay, St. James Mailing Address: White Sands P.O., Montego Bay, St. James School Office: Dorm Office: Ms. Diane Thompson jcsd_1@yahoo.com Caribbean Christian Centre for the Deaf (CCCD) PO Box 24, Granville P.O., Montego Bay, St. James Phone Number: Mrs. Dorette Russell cccdmb@cwjamaica.com is retained in all printings. 20