Deafness

BSC NURSING III YEAR

1. DEAFNESS Mr. Manikandan.T , RN., RM., M.Sc (N)., D.C.A .,( Ph.D ) Assistant Professor, Dept. of Medical Surgical Nursing, VMCON, Puducherry .

2. DEFINITION Loss of hearing either temporarily or permanently Also called anacusis

3. INCIDENCE Hearing impairment has been reported to occur in 3 of every 1000 births

4. CAUSES Impacted cerumen Foreign bodies Middle ear disorder Otosclerosis Stenosis of external ear Congenital Trauma Meningitis Prolonged exposure to loud noises Prenatal exposure to rubella

5. Classification

6. Conductive H.L It occurs in the outer and middle ear and impairs the sound being conducted from outer to inner ear.(because of defect in ossicle ) Means that vibration are not passing through from outer ear to inner ear

7. Sensorineural H.L It is caused by impairment of inner ear or the vestibulo cochlear nerve (C.N VIII)

8. MIXED H.L It is caused by combination of conductive and sensorineural

9. Central/ functional H.L It is caused by problem along the pathway from the inner ear to the auditory region of brain

10. Presbycusis Deafness occurs due to ageing

11. Based on severity Mild (26-40 db) Moderate (40-55db) Moderately severe (56-70 db) Severe (71-90 db) Profound (90db)

12. Based on onset Congenital: deafness at birth Acquired : deafness acquired after birth

13. Unilateral vs bilateral Single-sided deafness (SDD), or unilateral deafness, refers to hearing impairment in just one ear, while bilateral deafness is hearing impairment in both.

14. Clinical features Not responding when speaking others Straining to ear Difficulty to communicate Suspicion Loss of self esteem

15. Diagnosis H.C P/E Rinne’s test & weber’s test Audiometry Auditory brain stem response Tympanometry EOAEs(evoked otoacoustic emissions) measures sound originated in haircells of cochlea using microphone and transducer

16. CONTROL AND PREVENTION Avoid using cytotoxic drugs Avoid exposure to loud noises No buds for ear cleaning Protect ear from any injury Monitor hearing ability periodically Do not practice traditional way of poring hot oil into the ear

17. Hearing aids Behind-the-ear (BTE) hearing aids:  These consist of a dome called an earmold and a case, with a connection linking one to the other. The case sits behind the outer ear, with the connection to the dome coming down the front of the ear. The sound from the device is either electrically or acoustically routed to the ear. BTE hearing aids tend to last longer than other devices, as the electrical components are located outside the ear, meaning that there is less moisture and earwax damage These devices are more popular with children who need a sturdy and easy-to-use device.

18. In-the-canal (ITC) hearing aids:  These fill the outer part of the ear canal and can be seen. Soft ear inserts, usually made of silicone, are used to position the loudspeaker inside the ear. These devices fit most patients straight away and have better sound quality.

19. Completely in the canal (CIC) hearing aids:  These are tiny, discreet devices but not recommended for people with severe hearing loss. Bone conduction hearing aids:  These assist people with conductive hearing loss, as well as those unable to wear conventional type hearing aids. The vibrating part of the device is held against the mastoid with a headband. The vibrations go through the mastoid bone, to the cochlea. These devices can be painful or uncomfortable if worn for too long.

20. Tips for Hearing Aid Care Cleaning The ear mold is the only part of the hearing aid that maybe washed frequently. Wash ear mold daily with soap and water. Allow the ear mold to dry completely before it is snapped into the receiver. Clean the cannula with a small pipe cleaner–like device. Proper care of the ear device and keeping the ear canal clean and dry can prevent complications. Malfunctioning Inadequate amplification, a whistling noise, or pain from the mold can occur when a hearing aid is not functioning properly . Check for malfunctions: Is the switch on properly? Are the batteries charged and positioned correctly? If the hearing aid is still not working properly, notify the hearing aid dealer. Recognizing Complications Common medical complications include external otitis media and pressure ulcers in the external auditory canal. Signs and symptoms of these infections include painful ear , especially when the external ear is touched; canal swelling; redness; difficulty hearing; pain radiating to the jaw area; and fever .

21. Hearing Guide Dogs Specially trained dogs (service dogs) are available to assist the person with a hearing loss. People who live alone are eligible to apply for a dog trained by International Hearing Dog The dog reacts to the sound of a telephone, a doorbell, an alarm clock, a baby’s cry, a knock at the door , a smoke alarm, or an intruder. The dog alerts its master by physical contact; the dog then runs to the source of the noise. In public, the dog positions itself between the person with hearing impairment and any potential hazard that the person cannot hear, such as an oncoming vehicle or a loud, hostile person. In many states, a certified hearing guide dog is legally permitted access to public transportation, public eating places, and stores, including food markets .

22. Cochlear implants

23. Cochlear implants This thin electrode is inserted into the cochlea. It stimulates electricity through a tiny microprocessor placed under the skin behind the ear. A cochlear implant is inserted to help patients whose hearing impairment is caused by hair cell damage in the cochlea. The implants usually improve speech comprehension. The latest cochlear implants have new technology that helps patients enjoy music, understand speech better even with background noise, and use their processors while they are swimming

24. On the outside A microphone: This gathers sound from the environment. A speech processor: This prioritizes the sounds that matter more to the patient, such as speech. The electrical sound signals are split into channels and sent through a very thin wire to the transmitter. A transmitter: This is a coil secured with a magnet. It is located behind the outer ear and transmits the processed sound signals to the internally implanted device.

25. On the inside: A surgeon secures a receiver and stimulator in the bone beneath the skin. The signals are converted into electrical impulses and sent through internal wires to the electrodes. Up to 22 electrodes are wound through the cochlea. The impulses are sent to the nerves in the lower passages of the cochlea and then directly to the brain. The number of electrodes depends on manufacturers of the implant.

26. Indication – cochlear implant Bilateral SNHL above 90db where heraing aid is not helpful. Damage to cochlear nerve

27. Procedure – cochlear implant Simple moistoidectomy is done electrodes are placed in cochlea It cost around 4.5-8lakhs The patient after the cochlear implant needs intensive speech and auditory training for better discrimination of speech

28. Lip reading Also known as speechreading , lip reading is a method for understanding spoken language by watching the speaker's lip, facial and tongue movements, as well as extrapolating from the data provided by the context and any residual hearing the patient might have. People who became hearing impaired after they learned to speak can pick up lip reading rapidly; this is not the case for those who are born hearing-impaired.

29. Sign language This is a language that uses signs made with the hands, facial expressions, and body postures, but no sounds. It is used mainly by those who are deaf. There are several different types of sign languages. British Sign Language (BSL) is very different from American Sign Language (ASL). For instance, BSL uses a two-handed alphabet, whereas American sign language uses a one-handed alphabet.