1. Conductive hearing loss (CHL)
2. Sensorineural hearing loss (SHL)
3. Mixed hearing loss (MHL)
1. Central hearing loss
2. Functional hearing loss
Conductive hearing loss
• Conductive hearing loss is any
interference with the conduction of
sound impulses through the external
auditory canal, the eardrum, or the
• 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.
Sensorineural hearing loss
• Sensory hearing loss originates in the
cochlea and involves the hair cells and
• Sensorineural hearing loss results
from disease or trauma to the sensory
or neural components of the inner ear.
• Presbycusis is hearing loss caused
by the aging process that results
from degeneration of the organ of
• This degenerative process usually
begins at 50 yrs of age.
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
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
Functional hearing loss
• Functional hearing loss is a hearing loss
for which no organic cause or lesion can
• Also called psychogenic hearing loss.
• Precipitated by emotional stress.
• Malingering is a type of psychogenic
• In Malingering, there is no organic or
psychological cause. The patient is
pretending to be deaf for personal
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
– Ear infections
– Measles may cause auditory nerve damage
– Meningitis may damage auditory nerve or
– Auto immune disease
– Medulloblastoma or other brain tumors
– Syphilis from pregnant woman to fetus
– Premature birth
– Fetal alcohol syndrome in infants of alcoholic
– Neurological disorders
• Multiple sclerosis 13
• Family history of sensorineural impairment
• Congenital malformations of the cranial
• Low birth weight (1500 g)
• Use of ototoxic medications (eg:gentamycin,
• Recurrent ear infections
• Bacterial meningitis
• Chronic exposure to loud noises
• Perforation of the tympanic membrane
Causes of Conductive deafness
• Impacted Wax
• Otitis Externa
• Foreign Bodies
• Fluid in the ear
• Congenital defects of the
ear drum and ossicles.
• Perforation of the tympanic
• Traumatic: Barotrauma,
rupture of ear drum, skull
• Inflammation: AOM, COM,
Disorders of inner ear or
vestibulocochlear nerve or aging
Interruption in neural transmission
of sound to brain
• 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
The doctor will look in the ear for possible causes of hearing loss, such as
earwax or inflammation from any infection.
The doctor may ask the patient to cover one ear at a time to see how
well the patient’s hear words spoken at various volumes and how doctor
respond to other sounds.
A tuning fork evaluation may also reveal whether hearing loss is caused
by damage to the vibrating parts of your middle ear (including
eardrum), damage to sensors or nerves of inner ear, or damage to both.
THE RINNE TEST
A Rinne test evaluates hearing loss by comparing air conduction to bone
conduction. Air conduction hearing occurs through air near the ear, and
it involves the ear canal and eardrum. Bone conduction hearing occurs
through vibrations picked up by the ear’s specialized nervous system.
It compares the hearing sensitivity of a patient with that of an examiner.
The tuning fork is set into vibration, and the stem is placed alternately
againts the mastoid process (the bony protusion behind the ear).
During these more-thorough tests conducted by an audiologist, the
patient wear earphones and hear sounds directed to one ear at a time.
The audiologist presents a range of sounds of various tones and asks the
patient to indicate each time they hear the sound.
COMPARISON OF WEBER AND
Hearing Status Weber Rinne
Normal hearing Sound is heard
equally in both
Air conduction is
Sound is heard
best in affected
Sound is heard as
long or longer in
Sound is heard
best in normal
Air conduction is
in affected ear.24
• 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.
• Restore hearing
– Antibiotics: to treat infections
– Remove impacted wax or foreign
– Ceruminolytics for impacted wax
– Corticosteroids for inflammation
– Treat underlying disorders
• Hearing aids: Hearing aid is designed to amplify
• 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.
• 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
• Aural rehabilitation refers to services
and procedures for facilitating adequate
receptive and expressive
communication in individuals with
• If a hearing loss is permanent or
untreatable, aural rehabilitation may be
• Auditory training: Auditory training
emphasizes listening skills, so the person
who is hearing-impaired concentrates on
• 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. 33
• 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.
• 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.
• Surgery is indicated for conductive or
mixed hearing loss.
• To restore conductive hearing
• Assisted hearing in profound deafness
– Cochlear implants
– Middle ear implants (Semi-implantable hearing
• Tumour excision for acoustic neuroma
• Disturbed sensory perception: hearing related to
altered sensory reception and transmission
• Impaired verbal communication related to
• Impaired social interaction related to impaired
hearing and decreased communication skills
• Disturbed body image related to impaired hearing
and use of assistive hearing devices
• Ineffective coping related to difficult
• Deficient knowledge related to care of hearing aid
due to lack of prior experience
• Inspect ear canals for mechanical obstruction.
• Remove mechanical obstructions like cerumen or
• Assess hearing by use of a tuning fork, or verbal
cues to determine auditory ability at various
• Speak slowly with careful pronunciation of words.
• Add hand gestures, speak face to face and adjust
pitch downward without increasing volume.
• Introduce assistive devices such as hearing aids,
written communication, and sign language.
• Allow patient to verbalize feelings and grieving
about hearing loss.