Hearing loss and deafness Hearing loss or hearing

Hearing loss and deafness

�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

Etiological factors �Aging (presbycusis) �N 0 ise exposure �Disease �Injury to the ear �Chinldren – ear infections, congenital defects �At age 50, one of every eight persons is hearing impaired.

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

Types �Conductive hearing loss �Sensorineural hearing loss �Mixed hearing loss �Central and functional hearing loss �Noise induced hearing loss

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)

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

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

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.

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

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.

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

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

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

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.

�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

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.

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

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

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.

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.

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

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

HALF SHELL IN THE EAR

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

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 aid if an ear infection is present

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

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

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.

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.

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

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.

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

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

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.

Updates in hearing aids Bluetooth® and Wireless Accessories �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.