3. Types
1. Conductive hearing loss (CHL)
2. Sensorineural hearing loss (SHL)
3. Mixed hearing loss (MHL)
4. Others
1. Central hearing loss
2. Functional hearing loss
• Malingering
4. Conductive hearing loss
• Conductive hearing loss is any
interference with the conduction of
sound impulses through the external
auditory canal, the eardrum, or the
middle ear.
5. • Conductive hearing loss can be
caused by anything that interferes
with the ability of the sound wave to
reach the inner ear such as cerumen,
foreign bodies, infection.
6. Sensorineural hearing loss
• Sensory hearing loss originates in the
cochlea and involves the hair cells and
nerve endings.
• Sensorineural hearing loss results
from disease or trauma to the sensory
or neural components of the inner ear.
7. • Presbycusis is hearing loss caused
by the aging process that results
from degeneration of the organ of
Corti.
• This degenerative process usually
begins at 50 yrs of age.
8. Mixed hearing loss
• Mixed hearing loss occurs when an
individual has both conductive and
sensorineural hearing loss.
• This can be caused by a combination
of any of the disorders
9. Central hearing loss
• Central hearing loss occurs when the
central nervous system cannot
interpret normal auditory signals.
• This condition occurs with such
disorders as cerebrovascular accidents
and tumors.
10. Functional hearing loss
• Functional hearing loss is a hearing loss
for which no organic cause or lesion can
be found.
• Also called psychogenic hearing loss.
• Precipitated by emotional stress.
• Malingering is a type of psychogenic
hearing loss.
• In Malingering, there is no organic or
psychological cause. The patient is
pretending to be deaf for personal
gains.
11. Severity of hearing loss
Loss in Decibels Interpretation
0–15 Normal hearing
>15–25 Slight hearing loss
>25–40 Mild hearing loss
>40–55 Moderate hearing loss
>55–70 Moderate to severe hearing loss
>70–90 Severe hearing loss
>90 Profound hearing loss
12. Etiology
• Age: increasing age
• Exposure to loud noise
• Genetic
• Head injury
• Ototoxic drugs
• Illness
13. • Illness
– Ear infections
– Measles may cause auditory nerve damage
– Meningitis may damage auditory nerve or
cochlea
– Auto immune disease
– Mumps
– Otosclerosis
– Medulloblastoma or other brain tumors
– Syphilis from pregnant woman to fetus
– Premature birth
– Fetal alcohol syndrome in infants of alcoholic
mothers
– Neurological disorders
• Multiple sclerosis
14. Risk Factors
• Family history of sensorineural impairment
• Congenital malformations of the cranial
structure (ear)
• Low birth weight (1500 g)
• Use of ototoxic medications (eg:gentamycin,
loop diuretics)
• Recurrent ear infections
• Bacterial meningitis
• Chronic exposure to loud noises
• Perforation of the tympanic membrane
15. Causes of Conductive deafness
EXTERNAL EAR:
• Impacted Wax
• Otitis Externa
• Foreign Bodies
• Polyps
• Tumours
• Fluid in the ear
MIDDLE EAR
• Congenital defects of the
ear drum and ossicles.
• Perforation of the tympanic
membrane
• Traumatic: Barotrauma,
rupture of ear drum, skull
fracture
• Inflammation: AOM, COM,
• Neoplasms
• Otosclerosis
19. Disorders of inner ear or
vestibulocochlear nerve or aging
Interruption in neural transmission
of sound to brain
Sensorineural deafness
20. Clinical manifestations
• Tinnitus
• Increasing inability to hear when in a group
• Need to turn up the volume of the television
• Failure to respond or In appropriate response
to oral communications
• Excessively loud speech
• Strained facial expression
• Constant need for clarification of conversation
• Social withdrawal
22. COMPARISON OF WEBER AND
RINNE TESTS
Hearing Status Weber Rinne
Normal hearing Sound is heard
equally in both
ears.
Air conduction is
audible longer
than bone
conduction.
Conductive
hearing loss
Sound is heard
best in affected
ear (hearing
loss).
Sound is heard as
long or longer in
affected ear
(hearing loss).
Sensorineural
hearing loss
Sound is heard
best in normal
hearing ear.
Air conduction is
audible longer
than bone
conduction
in affected ear.
23. Prevention
• Minimize the exposure to trauma,
infection, ototoxic drugs.
• Avoid the risk factors.
• Wear ear protection to prevent
noise-induced hearing loss when
exposed to loud noise.
24. Management
Medical management
• Restore hearing
– Antibiotics: to treat infections
– Remove impacted wax or foreign
bodies
– Ceruminolytics for impacted wax
– Corticosteroids for inflammation
– Treat underlying disorders
26. • Hearing aids: Hearing aid is designed to amplify
sound
• Implantable middle ear hearing devices:
Implantable middle ear hearing aids are
implanted surgically, can improve sound
perception for patients with moderate-to-severe
sensorineural hearing loss.
27. • Cochlear implants: Cochlear implants are
surgically placed electrical devices that receive
sound and transmit the resulting electrical signal to
electrodes implanted in the cochlear of the ear.
• Sign language: It involves hand shapes,
movement of hands, arms, body and facial
expressions
29. • Aural rehabilitation refers to services
and procedures for facilitating adequate
receptive and expressive
communication in individuals with
hearing impairment.
• If a hearing loss is permanent or
untreatable, aural rehabilitation may be
beneficial.
30. Purpose
• To maximize the communication
skills of the person with hearing
impairment.
31. Components
• Auditory training: Auditory training
emphasizes listening skills, so the person
who is hearing-impaired concentrates on
the speaker.
• Speech reading: Also known as lip
reading. Speech reading can help fill the
gaps left by missed or misheard words.
• Speech training: The goals of speech
training are to conserve, develop, and
prevent deterioration of current
communication skills.
32. • Hearing Aids: A hearing aid is a device
through which speech and environmental
sounds are received by a microphone,
converted to electrical signals, amplified,
and reconverted to acoustic signals.
33. • 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, Inc. 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.
34. Surgical management
• Surgery is indicated for conductive or
mixed hearing loss.
• To restore conductive hearing
– Myringotomy
– Stapedectomy
• Assisted hearing in profound deafness
– Cochlear implants
– Middle ear implants (Semi-implantable hearing
device)
• Tumour excision for acoustic neuroma
35. MYRINGOTOMY
Myringotomy is the incision of the
tympanic membrane in order to drain
suppurative or non suppurative
effusion of the middle ear or to
provide aeration in case of
mulfunctioning eustachian tube.
This procedure may be combined with
insertion of a ventilation tube or
grommet which keeps the opening
