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
5.
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
8.
9.
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.
11.
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.
13.
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.
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
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.
34.
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.