1. Hearing loss and deafness

2. Hearing loss, or hearing impairment happens when one or more parts of the ear or ears are not functioning   Or
Hearing loss, hearing impairment, or deafness, is a partial or total inability to hear

3. Etiological factors Aging (presbycusis) N0ise exposure Disease
Injury to the ear
Chinldren – ear infections, congenital defects
At age 50, one of every eight persons is hearing impaired.

4. External ear
Impacted cerumen
Foreign bodies
External otitis
Middle ear
Otitis media
Serous otitis
otosclerosis
Inner ear
Menieres disease
Noise exposure
Presbycusis
ototoxicity

5. Types Conductive hearing loss Sensorineural hearing loss
Mixed hearing loss
Central and functional hearing loss
Noise induced hearing loss

6. Conductive hearing loss
Conductive hearing loss results form interference with the conduction of sound impulses through the external auditory canal, tympanic membrane or the ossicles of the middle ear.
It can caused by anything that blocks the external ear such as cerumen, infection or a foreign body.
It may also be caused by thickening, retraction, scarring or perforation of the tympanic membrane or any pathophysiologic change in the middle ear (tumours, previous surgeries, otosclerosis)

7. Sensorineural hearing loss
It results form disease or trauma to the inner ear, neural structures, or nerve pathways leading to the brain stem
Diseases that effect may be systemic or local infections or may be drug induced.
Systemic diseases – diabetes mellitus, arteriosclerosis and infectious disease such as measles, mumps and meningitis
Local diseases - neuromas of the eighth cranial nerve, otospongiosis, trauma to the head or ear, degeneration of the organ of corti

8. Mixed hearing loss
It is caused by a combination of conductive and sensorineural losses

9. Central and functional hearing loss
Central auditory dysfunction- it is a rare form of sensorineural hearing loss in which hearing ability remains intact but the patient is deaf because the central nervous system is unable to interpret normal auditory stimuli.
Central deafness can results from tumors or stroke
Functional hearing loss – by an emotional or a psychologic factor. The patient does not seem to hear or respond to hearing tests, but no organic cause can be identified.

10. Classification of hearing loss (based on severity)
The decibel (dB)is a measure of the loudness or intensity of sound.
A hearing loss of 15 to 50 dB is a mild to moderate loss (impaired hearing)
A loss of 50 to 80 dB is severe hearing loss
A loss of more than 80 dB in both ears is a profound hearing loss and referred as DEAF.

11. Noise induced hearing loss
Hearing loss due to exposure to noise accounts hearing impairment among people between 35 to 65 years.
If hearing loss results from a single exposure to a sudden loud noise or blast is referred as ACOUSTIC TRAUMA.
Hearing loss occurs over time from repeated injury from noise is referred as NOISE – INDUCED HEARING LOSS.

12. OSHA (OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION) has establish acceptable noise levels in work environment.
Ordinary speech is 60 dB and in heavy traffic it is 80 Db
Exposure to 85 to 90 dB for months can cause cochlear damage.
Based on OSHA regulations, the work environment exceeding noise above designated limits should wear EAR PROCTECTION DEVICES.

13. PRESBYCUSIS
Hearing loss associated with aging that becomes more common after 50
Changes in the delicate labyrinth structures over decades cause hearing loss

14. Clinical features Asking others to speak up Straining to hear
Cupping hand around ear
Answering questions inappropriately
Not responding when not looking at the speaker
Showing irritability with others
Increasing sensitivity to slight increases in noise level.
Family and friends who get tired of repeating or talking loudly are often first to notice hearing loss

15. Tinnitus Ringing noise
Tinnitus accompanies most sensorineural hearing losses and is often a warning of impending or worseing hearing loss
Persistent tinnitus is very annoying and the only cure is correct the underlying condition.

16. Deafness is often called the UNSEEN HANDICAP.
Patient refuses to admit or unaware of impaired hearing
Withdrawal, suspicion, loss of self esteem and insecurity are commonly associated with advancing hearing loss

17. Diagnostic features
History collection from the family members or friends
Physical examination
All diagnostic measures for testing ear function should done to rule out the exact cause of the hearing loss and also to treat the underlying disorders
CT scan, MRI, Blood test and cultures, audiometry, tympanometry, electronystagmograpy, arteriograpy.

18. Management Health promotion
Use of ear protectors while working in noisy conditions
Treating the ear disorders as early as possible
Avoiding drinking and driving
Avoid alcoholism
Organize health teaching programs in schools, communities and factories for preventing the hearing impairment

19. Immunizations
Various viruses can cause deafness as a result of fetal damage and malformations affecting the ear
Mumps, measles and rubella immunization should be provided
Infection during the first 8 week of pregnancy with rubella can leads to sensorineural deafness

20. Ototoxic substances
Chemicals used in industry (toluene, carbon disulfide and mercury) may damage the inner ear
Drugs – antibiotics, salicylates, diuretics and antineoplastic drugs
Symptoms of ototoxicity are tinnitus, impaired hearing and vestibular dysfunction
If symptoms develop immediate withdrawal of the drug may prevent further damage.

21. Assistive devices and techniques
Hearing aids – can assist individuals with hearing impairments.
Hearing aids should be fitted by an audiologist or a speech and hearing specialist after a through physical examination and hearing tests.
Hearing aids amplify sound in a controlled manner.

22. Hearing aids consist of
A microphone to receive sound waves from the air and change sounds into electrical signals
An amplifier to increase the strength of the electrical signals
A battery to provide the electrical energy to needed to operate the hearing aid
A receiver (loudspeaker) to change the electrical signals back into sound waves.

23. Types of hearing aids Five basic types
MICRO CIC (completely in the canal) hearing aid
ITC (in the canal ) hearing aid
HS (half shell) hearing aid
ITE (in the ear) hearing aid
BTE (behind the ear)hearing aid

24. HALF SHELL
IN THE EAR

25. Adjusting with the hearing aids
The nurse should explain the uses of it in detail
The patient must adjust the voices and household sounds
Experiment by increasing and decreasing the volume
If the patient is adjusted to the background noise, the patient is ready to go for a small party where several peoples talk simultaneously
After adapting to controlled situations, the patient can encounter environments such as shopping mall etc

26. Care of a hearing aid
When the hearing aid is not being worn, it should be keep in a dry, cool area
The battery should be disconnected or removed
Battery life is 1 -4 week (different based on the types)
Wash the ear mold frequently with mild soap and water
Toothpicks and pipe cleaners may be used to clear a clogged ear tip.
Turn the hearing aid off when not in use
Keep an extra battery
Do not wear ear aid if an ear infection is present

27. If the Hearing aid fails to work -
Check the on-off switch
Inspect the ear mold for cleanliness
Examine the battery for correct insertion
Change the battery
Check for any break in the aid

28. Implantable hearing devices
They are of two types
Cochlear implants
Bone conduction devices

29. Cochlear implant devices
It is used as a hearing device for people with severe to profound deafness who get little or no benefit from a hearing aid
The implant is an electronic hearing device that stimulates nerves within the inner ear
The system consists of a surgically implanted induction coil beneath the skin behind the ear and an electrode wire placed in the cochlea
The implanted parts interface with an externally worn speech processor
The device does not allow the person to hear speech but creates an awareness of environmental sounds such as doorbells or telephones etc.

30. Bone conduction devices
It transmit sound through the skull to the inner ear
Surgically implanted titanium screw implanted under the skin into the skull behind the ear
Once it heals, it is loaded with a vibrating hearing aid.

31. AURAL REHABILITATION
If hearing loss is irreversible and not surgically correctable, AURAL REHABILITATION is recommended
It includes auditory training, speech reading, speech training, sign language to maximize the communication of a hearing impaired person

32. Speech reading
It is also called as lip reading – helps in increasing communication skills.
The patient is able to use visual cues associated with the speech, such as gestures and facial expression to clarify the spoken message
In speech reading several words will look like alike (for ex: Oman, women )
The nurse should help the patient by using and teaching verbal and nonverbal communication techniques.

33. Nonverbal aids Draw attention with hand movements
Have speakers face in good light
Avoid covering mouth or face with hands
Avoid chewing, eating, smoking while talking
Maintain eye contact
Avoid distracting environments
Avoid careless expression
Use touch
Move close to better ear

34. Verbal aids Speak normally and slowly
Do not over exaggerate facial expressions
Use simple sentences
Write name or difficult words
Avoid shouting

35. Sign language
Sign language is used as a form of communication for deaf people
It is a visual – spatial language that involves gestures and facial features such as eyebrow motion and lip mouth movements.
Sign languages is not universal.

36. Bluetooth® and Wireless Accessories
Updates in hearing aids
Allows users to connect hearing instruments directly to peripheral accessories such as:
Cellular and home phone
Television and music players
Signaling devices like door bells and fire alarms
With this technology, hearing instruments are becoming more like personal communication devices.