1. Anatomy and Physiology of the Ear

2. 3 Parts of the Ear Outer, Middle, and Inner Ear
Part 1 OUTER EAR- Pinna to Tympanic Membrane
The “pre amp” –makes sound waves stronger
Pinna for humans has a poor design (too flat on head) try “cupping” ears and see how sound quality improves
Speed of sound-Speed of sound- at 68 degrees 1,125 feet per second = 756 mph
Higher temps= faster speed for sound

3. Does Ear Wax Have a Purpose?
2 important functions
1.Keeps skin in ear canal
soft
2. Keeps bugs out 
(they don’t like the taste)

4. What Causes Outer Ear Hearing Loss ?
Wax pushed up against eardrum (tympanic membrane)
from q-tip use 
Sharp objects that puncture tympanic membrane
Born with damaged ear canal or without pinna
Swimmer’s Ear - what is that?

5. Swimmer’s Ear Water + Germs or bacteria +
Wax in the auditory canal = mold 
Complications
How to treat it????

6. Tympanic Membrane Healthy TM is translucent is silvery in color
Red or pink or bulging shows an infection.

7. TYMPANIC MEMBRANCE Normal versus Infection

8. Part 2 - Middle Ear
Sound waves change to mechanical energy in the middle ear
½” chamber

9. What are the parts of the Middle Ear?
Back of tympanic membrane
3 small bones
Eustachian tube

10. Malleus, Incus, and Stapes 3 smallest bones in the body

11. Eustachian Tube What is the purpose? Drain cells/tissue
Equalize air pressure

12. What Causes Hearing Loss in the Middle Ear ?
Calcium deposits on bones
Solution ?
Loud sudden noises- firecracker, gunshot
Solution?
Trauma to the head- fall, car accident
Otitis media- what is that???

13. Otitis Media Most common ailment for children- Why???
Germs travel up eustachian tube-lodge in middle ear

14. Why are Parents concerned?
Ossicles do not vibrate correctly = 25dB hearing loss
Critical time for learning langauge
Treatments??

15. Antibiotics Children over medicated? Will condition improve by itself?
Are new strains of bacteria developing?
Risks for developing speech?

16. Ear Tubes- Chronic Otitis Media Small slit made in TM and tube put in for drainage from Middle Ear- most tubes fall out after a few months

17. Which is your “real voice”?
The voice YOU hear?
Sorry- you’re the only one who hears it
Why?
The voice on a tape?
This is your voice to the world 
                     

18. CONDUCTIVE HEARING LOSS
Any hearing loss occurring in the
OUTER or MIDDLE EAR
Examples ?????
Malformed pinna, too much wax,
swimmers ear (or water stuck in ear),
torn tympamic membrane, Otitis media, calcium deposits on ossicles,
torn muscles that control the ossicles
Conductive Hearing Loss can be repaired

19. The Inner Ear Cochlea semi- circular canals
auditory nerve (8th cranial nerve)
Note the changes of energy as the sound waves come through each part of the ear
Wave to mechcanical to hydralic to electrical

20. Entrance to the Inner ear

21. The 3 bones vibrate causing a disturbance at the “Oval Window”

22. Parts of the Inner Ear Cochlea Semi-circular Canals
Auditory (8th cranial) nerve

23. Why do you get dizzy? Liquid in Semi –Circular canals
Information from cilia sent to brain
Must match info sent from eyes
Dizzy = brain doesn’t know what to follow
Have students spin

24. The COCHLEA Size of a pea Fluid –filled
Contains up to 20,000 cilia or hair-like nerve endings

25. Movement of the fluid stimulates the cilia
Creates Electrical impulses

26. Auditory nerve- carries electrical impulses from cilia (in cochlea and semicircular canals) to the brain for interpretation

27. Sensorineural Hearing Loss (Hearing loss in the Inner Ear)
Known etiologies-
Multiple Sclerosis
Leukemia
Sickle cell
syphilis
Bacterial infection( meningitis)
Mumps
ototoxic drugs (aspirin)
tumor (from cell phones?)
noise explosion
menieres disease
genetic connexin 26
toys- noise levels
membrane rupture
airbag (ruptures tympanic membrane, tinnitus hearing loss)
Premature birth
unknown
Sensorineral- of the inner ear

28. Review--Pathway of Sound
Sound waves enter pinna travel through auditory canal
Sound waves strike tympanic membrane causing vibrations (mechanical energy)
Vibrating TM causes ossicles to vibrate
Vibrating stapes bone at oval window generates movement of cochlear fluid (Hydralics)
Fluid movement stimulates cilia- lined cochlea
Cilia sends electrical impulses along auditory nerve to brain for interpretation