Download 1.3.2 Conduction vs. Sensoneural Deafnness

1.3.2 Conduction vs. Sensoneural
Deafnness
Causes and Corrections
• Conductive hearing problems are those that
disrupt the conduction of sound through the
outer and middle ear.
Conductive Hearing Loss
• Affects hearing before the sound reaches the
cochlea and the nerve receptors of the inner
ear.
The Good News
• Conduction deafness is often temporary or
curable
Causes of Conduction Deafness
• Otitis Media
•
•
Middle ear infection
Chronic suppurative otitis media –
1.Peferation of the tympanic membrane
2. Bacterial infection
l
“Glue Ear” Collection of fluid in the middle ear - (otitis
media with effusion)
• Thick, sticky fluid collects behind the eardrum.
• The fluid blocks the middle part of the ear and
can cause impaired hearing.
• It usually affects children.
Interventions for “Glue Ear”
• Antibiotics
• Ear Tubes (grommet)
Cerumen
• Ear Wax
Blockage of the outer ear, usually by
wax.
Otosclerosis
• Ossicles of the middle ear harden and become
less able to vibrate.
Otosclerosis
• Approximately one-third of all persons with
impaired hearing have this condition.
• Hereditary
• Damage to the ossicles, e.g. by serious infection or
head injury.
• Perforated (pierced) eardrum, which can be caused
by an untreated ear infection (chronic suppurative
otitis media), head injury or a blow to the ear, or
from poking something in your ear.
Interventions
• Hearing aids -usually effective for conductive
hearing loss.
http://www.nlm.nih.gov/medlineplus/ency/imagepages/8685.htm
Interventions
• Stapedectomy - top part of the stapes is removed. A
laser beam is used to create a small hole in the footplate and
a metal tube is inserted. A wire attached to the tube connects
to the incus and transmits vibrations to the inner ear.
Sensorineural deafness
• Sensorineural deafness is decreased hearing
or hearing loss that occurs from damage to
the inner ear, the auditory nerve, or the
brain.
• Sensorineural hearing loss is most often due
to a loss of hair cells (sensory receptors in the
inner ear).
• Sensorineural deafness can be present at birth
(congenital), or it can develop later in life
• (SNHL) accounts for about 90% of all hearing
loss
• Found in 23% of population older than 65
years of age
Causes of Sensorineural Deafness
• Presbycusis - hearing loss that gradually
occurs in most individuals as they grow older
Presbycusis
• Aging
• Loud noises (acoustic trauma)-
http://www.healthpractical.com/tag/great-stressors
Duration
• The period of time the
sound continues to exist.
• “Exposure to sound levels of
85 decibels, the equivalent
of a lawn mower or food
blender, may cause
permanent hearing loss if
endured for 8 hours per day
for a prolonged period”
Healthy Cochlea
The cilia ( sensory
hairs) appear normal
Damaged Cochlea
Loss of cilia as a
result of Noise
Occupational Risk
• Some jobs carry a high risk for hearing loss,
such as:
• Airline ground maintenance
• Construction
• Farming
• Jobs involving loud music or machinery
Interventions:
• Hearing aid
• Hearing aids will not restore normal hearing
or eliminate background noise.
• Amplfies sound
• Adjusting to a hearing aid is a gradual process
that involves learning to listen in a variety of
environments and becoming accustomed to
hearing different sounds.
Prevention
http://www.rainbowsafety.co.uk/warning-noise-levels--wear-ear-protection-sign-map-43-1438
Cochlear Implants
• Auditory understanding of the environment
and helps in understanding speech.
• Does not reinstate or generate normal
hearing.
• Compensates for damaged or non-working
parts of the inner ear.
• Surgically implanted under the skin
behind the ear, this device is made of
four basic parts:
• microphone picks up sound from the
environment
• speech processor translates the sounds
picked up by the microphone into
signals
• transmitter and receiver/stimulator
receive these signals and convert them
into electric impulses
• electrodes send these impulses to the
brain.
Cholesteatoma
• Benign skin growth in the middle ear, causing
deafness and vertigo
Intervention
• surgical removal of the cyst.
Acoustic neuroma
• A benign (non-cancerous) tumor affecting the
auditory nerve
http://med.mui.ac.ir/slide/clinical/ent/AcousticNeuroma.jpg
Intervention
• Radiosurgery The use of ionizing radiation,
either from an external source such as an xray machine or from an implant, to destroy
cancerous or other diseased tissue.
http://www.health.wvu.edu/services/neurosurgery/gamma-knife/images/header.jpg
Tinnitus
• Ringing in the ears
• Most tinnitus comes from damage to the
microscopic endings of the hearing nerve in
the inner ear.