1. By InnaKorda, MD, Institute of Nursing, TSMU
Ears
By InnaKorda, MD,
Institute of Nursing, TSMU

2. Ear Anatomy

3. Ear Physiology External Ear Middle ear Inner ear
External auditory meatus funnels sound waves, which reflect off the tympanic membrane to produce vibrations
Cerumen (ear wax) protects the tympanic membrane from foreign substances
Middle ear
Malleus, incus, and stapes and eustachian tube
Function to:
Conduct sound vibrations from tympanic membrane (outer ear) to cochlea (inner ear)
Protect the cochlea by reducing the amplitude of sounds
Eustachian tube allows equalization of air pressure
Inner ear
Vestibule and semicircular canals
Allow brain to sense body position and relation of angle of head to gravity
Cochlea
Transfers vibrations from stapes into nerve impulses

4. The outer ear catches the waves of sound and funnels them down the ear canal (about an inch long) and flush up against the ear drum. The ear drum (tympanic membrane) is the boundary between the outer ear and the middle ear.

5. In the middle ear, the malleus picks up the vibrations from the eardrum, passes them to the incus which then passes them to the stapes. The stapes terminates in a tiny footplate that fits precisely into the contact point or window of the inner ear.

6. The window of the inner ear is the contact point of the cochlea
The window of the inner ear is the contact point of the cochlea. The vibrations set up rolling waves in the cochlear fluid which stimulate different areas of the membrane, which rubs against specialized cells called hair cells. This friction creates electrical impulses transmitted by the cochlear nerve.

7. CN VIII is responsible for signal transduction from vestibule and cochlea to the brainstem. From brainstem, a signal is sent to the cerebral cortex to interpret the sound.

8. Hearing Loss Conductive Sensorineural
Mechanical dysfunction of external or middle ear
Partial hearing loss
May be caused by impacted cerumen, foreign bodies, perforated tympanic membrane, pus or serum in middle ear, or otosclerosis (hardening of stapes)
May be fixed
Sensorineural
Dysfunction of inner ear, CN VIII, or cerebral cortex
Cannot be fixed
Otosclerosis – decrease in mobility of oscicle

9. Developmental Considerations
Infants
Greater risk for otitis media (middle ear infections) due to shorter eustachian tube
Aging
Cilia lining ear canal become coarse and stiff, impeding sound waves
Cerumen more common
Dry cerumen – gray and flaky. More common in Asians and Native Americans
Wet cerumen – brown and moist. More common in whites and blacks
Presbycusis - degenerative sensorineural hearing loss
Auditory reaction time increases

10. Obtaining History Earaches? (otalgia) Infections?
Location, character, intensity, associative and alleviating factors
May be directly due to ear disease or maybe referred pain from a problem in teeth or oropharynx
A viral or bacterial upper respiratory infection may migrate up the eustachian tube and involve the middle ear
Infections?
Frequency? Occurred in childhood?
Discharge? (otorrhea)
May suggest infection or perforated eardrum
Typically with perforation, ear pain  drainage
Otitis externa – purulent, sanguineous, or watery
Acute otitis media with perforation – purulent discharge

11. More History Trouble hearing? Ringing in ears? (tinnitus) Medications?
Gradual our sudden?
Presbycusis – gradual sensorineural hearing impairment in the elderly
Hearing loss due to trauma is often sudden
Ringing in ears? (tinnitus)
May be a result of medication
Medications?
Some are ototoxic
Vertigo? (spinning)
Subjective – person feels like he or she spins
Objective – person feels like room spins
Environmental noise
Noise-induced hearing loss

12. Lesions of External Ear
Otitis Externa
Gouty Tophi

13. Assessing External Ear
Size and Shape
normal is 4-10cm tall
Skin conditions
Note edema, inflammation, lesions
Tenderness
Location?
Pain in pinna indicates otitis externa
Pain at mastoid process indicates mastoiditis or lymphadenitis
External Auditory Meatus
Atresia – absence or closure of ear canal
Otitis externa may cause purulent discharge
Otitis media may cause rupture of tympanic membrane
If drainage present following trauma, possible basal skull fracture. Perform glucose test (CSF (+) for glucose).

14. Inspecting Using Otoscope
Pull the pinna up and back in adult, straight down in children under 3 years
Hold otoscope upside down and place dorsal side of hand along person’s cheek
Insert speculum slowly and avoid touching the inner section of canal wall, which is sensitive and may cause pain.

15. Inspecting the External Canal
Note any redness or swelling, lesions, or foreign bodies
If discharge present, note color and odor
Otitis
Externa

16. Inspecting the Tympanic Membrane
Normal is shiny and translucent
Flat, slightly pulled in at the center
Valsalva maneuver causes tympanic membrane to flutter, used to assess drum mobility
Which tympanic membrane
is perforated?

17. Testing Hearing Acuity
Voice test
Whisper two syllable words into one of the person’s ears, while covering the other one. Ask person to repeat what you’ve said.
Tuning fork tests
Measure hearing by air conduction or bone conduction
Weber test
Rinne test

18. Weber Test
Tuning fork is struck and placed on head or forehead, equal distance from both ears
Used to determine if hearing loss is more extensive in one ear than the other
This test cannot confirm normal hearing, because hearing defects affecting both ears equally will produce an apparently normal test result

19. Rinne Test Compares air conduction and bone conduction
Place stem of vibrating fork on mastoid process and ask when sound goes away
Quickly invert the fork so the vibrating end is near the ear canal. The person should still hear a sound
Normally the sound is heard longer by air conduction rather than bone conduction
In conductive hearing loss, sound heard longer by bone conduction

20. Normal Hearing

21. Conductive Hearing Loss

22. Sensorineural Hearing Loss

23. Infants and Children Save otoscopic examination until the end
May help to show otoscope to child and let him or her play with it
Stabilize (or ask a parent for help) the child’s head in order to prevent movement
Pull pinna straight down
In infants, the tympanic membrane may look thick and opaque after first few days or after crying
Tympanostomy tubes may be in place if drainage occurs as a result of otitis media

24. Abnormalities in the Ear Canal
Acute Otitis Media
Otitis Externa
Excessive Cerumen

25. Question 1
A nurse is performing a voice test to assess hearing. Which of the following describes the accurate procedure for performing this test?
Stand 4 feet away from the client to ensure that the client can hear at this distance
Quietly whisper a statement and ask the client to repeat it
Whisper a statement with the examiner’s back facing the client
Whisper a statement while the client blocks both ears

26. Question 2
A nurse is caring for a client who is hearing impaired. Which of the following approaches will facilitate communication?
Speak frequently
Speak loudly
Speak directly into the impaired ear
Speak in a normal tone

27. Question 3
A client is diagnosed with a disorder involving the inner ear. Which of the following is the most common client complaint associated with a disorder involving this part of the ear?
Hearing loss
Pruritus
Tinnitus
Burning in the ear

28. Question 4
Which of the following statements made by a parent should make the nurse suspicious that the tympanic membrane of a young child has ruptured?
“She has been crying all night, but she feels better this morning.”
“She has some bloody, yellow-looking stuff coming out of her ear.”
“My child does not seem to hear very well.”
“My child’s earwax is dark brown.”

29. Question 5
While examining the internal ear, the nurse observes the light reflex on the tympanic membrane. What does this finding indicate?
Presence of pus
Fluid accumulation
Scar tissue
Normal finding