Deafness and Hearing Impairment presentation

Deafness and hearing impairment notes

1. Deafness and Hearing Impairment BY MR C. ZULU

2. Introduction Hearing impairment refers to partial or complete loss of the ability to hear from one or both ears. The level of impairment can be mild, moderate, severe or profound. Deafness refers to the complete loss of the ability to hear from one or both ears. There are two major types of hearing impairment defined according to where the problem occurs

3. Conductive Hearing Impairment: is related to how the ear gathers sound. This involves a problem in the outer or middle ear. The hearing process is medically or surgically treatable. Sensorineural Hearing Impairment : is related to how the nervous system transmits sound to the brain. This is usually due to a problem with the cochlear and occasionally with the hearing nerve ( vestibulocochlear nerve). This condition is usually permanent and requires rehabilitation with hearing aids. Common causes are excessive noise, birth injury, head trauma and ageing ( presbycusis ).

4. Other Types Mixed Hearing Impairment : this refers to hearing impairment which results when the conductive hearing impairment is superimposed on sensorineural hearing impairment. Central Hearing Impairment : this refers to hearing impairment/loss that has its underlying difficulty in the central nervous system. In this case the hearing difficult cannot be explained adequately on either conductive or sensorineural basis.

5. Causes of Deafness and Hearing Impairment/Loss Hearing Impairment/Loss/Deafness can be inherited. Hearing impairment may also be caused before or during birth for several reasons and these may include: premature birth or low birth weight in which the baby lacks enough oxygen to breathe, rubella, syphilis or certain other infections in a woman during pregnancy. Also the use of ototoxic drugs or drugs, such as, aminoglycosides (gentamycin, streptomycin, aspirin) can cause damage to the inner ear if incorrectly given during pregnancy. Jaundice or hyperbilirubinaemia in a new born can also damage the 8th cranial nerve .

6. 3. Infectious disease such as meningitis , measles , mumps , severe cerebral malaria and chronic ear infections in the young can cause deafness. 4. Loud noises such as gunfire or massive explosions, traffic sounds, noisy machinery, etc., can damage the middle ear and especially the inner ear and weaken hearing eventually. 5. Age: as people age, accumulated exposure to noise and other factors including general body tissue degeneration in the aged may lead to hearing impairment or deafness. This kind of hearing impairment occurs gradually as people grow older and begins in the 40s growing worse from there onwards..

7. W.H.O. grades of hearing impairment/loss Grade 0 No or very slight hearing problems Able to hear 25 decibels (dB) in the better ear (able to hear whispers) Grade 1 Slight Impairment 26 – 40 decibels in the better ear Able to hear and repeat spoken words in normal voice at 1 metre . Hearing Aids not necessary

8. Grade 2 Moderate Impairment 41 – 60 decibels in the better ear Able to hear words and repeat spoken words in a raised voice at 1 metre Hearing Aids usually recommended

9. Grade 3 Severe Impairment 61 – 80 decibels in the better ear Able to hear some words when shouted into the better ear. Hearing Aids are needed definitely, if not available Lip Reading and Sign Language should be taught.

10. Grade 4 Profound Impairment including Deafness 81 or greater decibels in the better ear. Unable to hear or understand even a shouted voice in the nearest ear. Hearing aids may help, Rehabilitation is needed, and Lip Reading, signs and sign Language should be taught.

11. Signs and symptoms of deafness and hearing impairment Asking to have things repeated frequently during conversations Giving irrelevant answers to questions Lack of attention and day dreaming Hearing much better when watching the speaker’s face Tendency to withdraw from activities necessitating conversations

12. 7. Deviations in speech, especially sound articulation 8. Delayed speech and language development 9. Having more response to vibration and touch than speech and sound in the surrounding environment. 10.The person communicates more through the use of gestures, signs like vocalization and speech 11.There is behavior suggestive of an emotional immaturity such as being demanding, fearful, having temper tantrums, etc. 12.Depression

13. 13. Insecurity whenever they see others talking, the person things the people are talking about them (over suspicious). 14.“False pride” e.g. pretends as though they have heard when not. 15.Withdrawal from social contacts

14. Signs and symptoms in preschool children Absence or little bubbling from the infant and failure of the child to produce certain words in which consonants are distinct e.g. gaga, mama, baba etc. Delayed speech and language development More response to vibration and touch than speech and sound in the surrounding environment and undue alertness e.g. a child needing to be touched before waking up;

15. 4. The child makes easy wants known through the use of gestures and signs than vocalization and speech attempt 5. Behavior suggestive of emotional immaturity such as being demanding, fearful, having temper tantrums, etc. 6. Difficulty in perceiving what is said regardless of the intensity of the speaker’s voice.

16. Assessment of hearing and investigations Hearing tests are mainly concerned with two major things Sensitivity, speech discrimination. Sensitivity has to do with one’s ability to hear or respond to stimuli. While speech discrimination has to do with one’s ability to clearly distinguish different speech sounds. The basic instrument used for the measurement of hearing is called an Audiometer

17. However the initial investigation done is history taking and physical examination which involves examination of the pinna, especially in the hope of ruling out any surgical scars, tumors or warts which may affect hearing. Thereafter the level of hearing is tested with the voice, and it is very important to ensure that when one ear is being tested, the sound should not be heard in the other ear. It is tested with a tuning fork.

18. Weber test Where a tuning fork is placed on the forehead or above the head of the patient and the sound wave moves through the bone equally to both cochlear, the patient is then asked to which ear the sound is heard louder. In unilateral sensorineural deafness the sound will obviously be heard in the better ear with a normal cochlear. However, in unilateral conductive deafness, the sound is heard louder in the deaf ear which is masked from external sounds by conductive deafness and can therefore concentrate sound better on bony conducted sounds.

19. Medical Treatment If the deafness or hearing impairment is caused by perforation of the eardrum, systemic antibiotics are given by mouth to prevent further infections. Idiopathic (sudden) deafness is treated with a great variety of drugs including steroids and vasodilators. However, no treatment has proved valuable. Nevertheless, corticosteroids are usually prescribed and bed rest is usually advised. Tinnitus is said to be caused by spasms of blood vessels supplying the inner ear and there is no likelihood that any therapy medical or surgical relieves it, Hence the patient is encouraged to wait for tinnitus to decrease altogether on its own.

20. Surgical Treatment A sensorineural hearing loss of vertigo that persists for more than a few hours after an injury suggests something has penetrated the inner ear and in this case a surgical procedure called tympanotomy is usually performed to inspect the area and repair the damage. Furthermore, persistent hearing loss suggests a disruption of the ossicles which are repaired surgically through Tympanoplasty

21. However, when vertigo is disturbing and disabling and hearing loss deteriorates greatly, the cochlear and semicircular canals can be removed in a surgical procedure called labyrinthectomy . Small tumours are removed by microsurgery to avoid damaging the facial nerves; large tumours require extensive surgery though.

22. Prevention of Deafness The following strategies are useful in preventing deafness: Proper care of the healthy ear ; Wax should not be cleaned out of the ear routinely as it acts as a protective mechanism. It lubricates the skin and traps foreign material that enters the ear canal. Early and adequate treatment of ear infections Any disease of the ear that causes prolonged symptoms, such as, pain, swelling, drainage (plagued feeling) or decreased hearing should be promptly assessed and treated appropriately by the physician.

23. 3. Prevention of trauma to the ear; People should be taught to avoid inserting hard objects into the ear canal. Ear obstruction with any object, insertion of unclean articles or solutions in the ear, and swimming in water polluted with particles can lead to damage of the tympanic membrane or to ear infection. 4. Early detection of hearing loss; Early detection of hearing loss is important so that the cause of the loss can be diagnosed and hopefully the problem can be corrected and arrested. The earlier the problem is diagnosed the easier it may be to treat.

24. 5. Monitoring side effects of ototoxic drugs; Some drugs may affect the cochlear and vestibule of the ear or 8th cranial nerve. Persons taking ototoxic drugs need to know the side effects and signs and symptoms of these drugs to prevent the loss of hearing from developing 6. Monitoring noise pollution; The most common type of occupational hearing loss in our society is caused by loud noise. Exposure to levels greater than 85 – 90 decibels for months or years can cause cochlear damage. Persons working in areas of high decibel noise must wear soundproof ear plugs.

25. 7. Periodic ear examination; Examination of the ear and hearing is recommended every 2-3 years because ageing frequently causes degenerative changes in the ear as well as in other body tissues.

26. Many cases of sensorineural hearing impairment can be prevented through: Immunizing children against childhood illnesses including meningitis and mumps Immunizing women of child bearing age [15 – 45 years] against rubella before pregnancy. Testing for and treating syphilis and certain other infections in pregnant women Improving antenatal and perinatal care Avoiding the unnecessary use of ototoxic drugs unless prescribed by a qualified health personnel and properly monitored for correct use.

27. Rehabilitation of Deaf and Hard of Hearing Individuals This is unusually directed at obtaining maximum use of any remaining hearing ability and teaching the client more effective use of the senses of vision and touch. Rehabilitation is affected by the client’s age and the severity of the impairment. It is more difficult to rehabilitate an old person with some visual reduction. Infant rehabilitation will require a specialist who can help them learn how to communicate.

28. 1. Speech or lip reading This is the ability to understand speech through observation of the lip and tongue movements, facial expression, gestures and body movements. This is the purpose of providing effective communication.

29. 2. Sign language This is the ability to make communication possible by means of hand signals. Various hand signals represent different letters of the alphabet and words which are taught by specialists.

30. 3. Speech therapy This is speech training that is done when the patient cannot hear his own voice or other people’s voices. It is directed at people who are deaf with speech problems and also towards counselling. It prevents possible deterioration of speech skills related to impaired hearing.

31. 4. Auditory training Auditory training is another aspect of rehabilitation which emphasizes on speech discrimination and listening skills and use residual hearing.

32. 5. Vocational training The employable person with impaired hearing may require vocational training as part of rehabilitation. This is so because some deaf persons have the additional problems of poor balance due to damage to the inner’s vestibular portion and unusual sensitivity to noise even though hearing is impaired. Consideration should be given to the presence of these problems in selecting appropriate rehabilitation for deaf individuals.

33. 6. Hearing aids These amplify sound so as to compensate the reduced hearing sensitivity. A hearing aid is any kind of mechanical or electrical device which improves hearing. The otologist determines whether the patient’s hearing can be improved surgically, mechanically or medically with a hearing aid. Hearing aids can maintain communication. While hearing aids may improve the person’s hearing, they never restore hearing to normal level. They may amplify sound but not improve the ability to hear.

34. 7. Hearing guide dogs Specially trained dogs are available to assist a person with a hearing loss. People who live alone are eligible to apply for a trained dog. At home the dog reacts to a sound of telephone, a door bell, a small alarm or an intruder. The dog doesn’t bark but alert its master by physical contact, and then runs to the source of noise. In public, the dog positions itself between the hearing impaired person and any potential hazard that the person can’t hear such as an oncoming vehicle or a loud hostile person.