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1. HEARING

2. Anatomy of the Ear

3. Areas of the Ear
 Outer Ear (Hearing)
 Pinna(Auricle)
 External Auditory Canal/Meatus
 Ceruminous glands
 Tympanic Membrane(Eardrum)

4. Areas of the Ear
 Middle Ear (Hearing)
 Auditory Ossicles
 Malleus/Hammer
 Incus/Anvil
 Stapes/Stirrup
 Tiny Muscles
 Tensor tympani
 Stapedius
 Eustachian tube

6. Areas of the Ear
 Inner Ear
 Hearing and Equilibrium
 Oval Window
 Round WIndow
 Bony Labyrinth with perilymph
• Membranous Labyrinth with endolymph

7.  Bony Labyrinth
 Vestibule
• Equilibrium Receptors
• Utricle and Saccule
 Semicircular Canals
• Equilibrium Receptors
• Ampulla
 Cochlea
• Hearing receptors
• Modiolus
• Scala Vestibuli, Scala Tympani, Scala Media
• Organ of Corti with Hair cells

10. Physiology of Hearing
 The auricle directs sound waves into the
external auditory canal
 When sound waves strike the eardrum, the
pressure of air cause the eardrum to vibrate
 Vibration of the eardrum cause the malleus,
incus and stapes to vibrate.
 As the stapes move back and forth, it pushes the
membrane of the oval window in and out.

12.  The movement of the oval window sets up flid
pressure waves in the perilymph of the cochlea.
As the oval window bulges inward, it pushes the
perilymph of the scala vestibuli.
 Pressure waves are transmitted from the scala
vestibuli to the scala tympani and eventually to
the round window, causing it to bulge outward in
the middle ear.

14.  As the pressure waves deform the walls of the
scala vestibuli and scala tympani, they also push
the vestibular membrane back and forth creating
pressure waves in the endolymph inside the
scala media.
 The pressure waves in the endolymph cause the
basilar membrane to vibrate, which moves the
hair cells of the spiral organ against the tectorial
membrane. Bending of the stereocilia produces
receptor potentials that ultimately lead to the
generation of nerve impulses.

18. Ear Disorders

19. Deafness
 Conductive Hearing Loss
 Occurs when sound cannot reach the cochlea
 Causes
 Obstruction (Cerumen Impaction)
 Mass loading ( Middle ear effusion)
• Ear canal is very sensitive
• Removal with a loop or hook
 Stiffness effect (Otosclerosis)
 Discontinuity (Ossicular disruption)
• Resorption of bone
• Stapedectomy

20.  Symptoms
 Tinnitus - clicking in the ears
 Feeling of fullness in the ear
 Sounds are faint or non existent
 Needing everything to be repeated
 Withdrawal from social activities
 Depression and embarrassment

21.  Treatment
 Removal of the offending obstruction
 Surgery
 Hearing Aids
 Draining of fluids that have built up
 Softening and removal of excessive ear wax
 Antibiotics such as oral medication or ear drops

22.  Sensorineural Hearing Loss
 Disturbance in the inner ear in the cochlea
or the acoustic nerve to the brain
 Causes
 Long-term exposure to loud sounds
 Ototoxic medications
 Trauma
 Aging

23.  Symptoms:
 Unable to hear high tones (high frequency
hearing loss)
 Can not understand or hear speech
 Loud TV volume
 Always needing conversation repeated
 Retreat from social activities and interaction
with others
 Depression

24.  Treatment
 Remove ear wax or use of antibiotics to treat
an ear infection
 Intratympanic steroids may be effective
 Hearing aids
 Surgery:
 Tympanoplasty for repair of a perforated eardrum
 Myringotomy tubes surgically inserted to drain the
ear of fluids caused by infections.
 Cochlear implant

25.  Presbycusis
 Causes
 Atrophy of the sensory cells
 Loss of neuron in the cochlea and CNS
 Atrophy of the wall of cochlea
 Mechanical change of the outer ear

26.  Meniere’s Disease
 Disorderof the middle ear with an increase
amount of endolymph that enlarges the
membranous labyrinth
 Treatment
 Symptomatic relief

27.  Symptoms
 Hearing loss of several hours or more
 Vertigo,
 severe nausea,
 vomiting
 sweating
 Tinnitus
 Feelings of fullness or pressure in the ear
 Headache
 Abdominal pain
 Diarrhea

28.  Otitis Media
 Infectionof the middle ear caused mainly by
bacteria and associated with infections of the
nose and throat.
 Causes
 Allergies
 Persistent infections
 Ear trauma
 Swelling of the adenoids

29.  Symptoms
 Pain
 Malaise
 Fever
 Reddening
 Outward bulging of eardrum

30.  Treatment
 Oral or ear drop antibiotics
 Adenoidectomy
 Surgical repair of ruptured eardrum
 Otitis media complications may include:
 Cyst of the middle ear (cholesteatoma)
 Facial paralysis
 Mastoiditis
 Epidural abscess (inflammation surrounding the brain)
 Partial or profound hearing loss

31.  Mixed Hearing Loss
 Combination of conductive and sensorineural
losses
 Chronic ear infection that is a fairly common
diagnosis could result in a defect ear drum
and/or middle ear ossicle damages. Surgery
is often attempted but not always successful.
 Functional Hearing Loss
 Individual
does not respond to voice and
appears not to hear

32. Treatments
 Hearing Aid
 an electroacoustic device which typically
fits in or behind the wearer's ear, and is
designed to amplify and modulate sound
for the wearer.
 receives sound, amplifies it, and
transmits this stronger sound down the
ear canal into the ear.
 sound is amplified to make the weak and
distorted signals more audible.

33. The microphone - picks
up the sound and sends it
to the amplifier.
The amplifier - makes
the sound louder.
The receiver - sends the
amplified sound into the
ear canal.
The battery - supplies
the power to the hearing
aid.

35. Cochlear Implants
 Surgically implanted electronic device
 Provides a sense of sound to a person who
is profoundly deaf or severely hard of hearing.
 Referred to as bionic ear

36.  can restore hearing in patients suffering
deafness due to loss of sensory hair cells in
their cochlea
 electrical hearing is much less rich than natural
hearing, and offers only very limited
appreciation of musical melody, or speech
understanding in noisy environments.

37.  Sound no longer travels via the ear canal
and middle ear
 It will be picked up by a microphone and
sent through the device's speech
processor to the implant's electrodes
inside the cochlea.