The document discusses the anatomy and physiology of the ear and hearing process. It describes the three main parts of the ear - outer, middle, and inner ear. It explains how sound is conducted through the ear canal to the cochlea, where it is transduced into neural signals and transmitted to the brain. The document also discusses types of hearing loss and common causes. Additionally, it provides an overview of how hearing aids work and the different styles available.

1. Gerard Recio
Kamille Salem
Zaira Rivera
Mica Pusing
3OTB

2.  To distinguish between the two types of
deafness
 To know the proper method of performing
the Rinne and Weber tests

4. In doing the experiment there are two tests that we should
perform. First is the Rinne test. From our group we chose the
representative to whom we would perform the experiment.
One ear of the subject was plugged. On the heel of the hand, a
tuning fork was set in motion by striking it. At the level of the
upper portion of the unplugged ear canal, the stem of the
tuning fork was placed on the mastoid processes. When the
sound from the vibrating fork disappears, the subject was
asked to make a signal. Then, place the line of the fork in front
of the unplugged ear at a distance of 3 to 6 inches. Whether
the subject hears any sound or not indicate it. The procedure
was repeated on the other ear.

5. For the next test which is the Weber’s test,
another member of the group was selected to
be the subject. On the heel of the hand, the
tuning fork was strike. On the forehead of the
subject the stem of the tuning fork was
placed. We asked the subject to compare the
sounds that was heard in each ear. We
indicate whether the sound was heard
equally or not.

7.  Outer ear – pinna, external auditory canal
 Middle ear – tympanic membrane, three
ossicles and the Eustachian tube
 Inner ear – cochlea, semicircular canals,
nerves
* All three parts are involved in hearing
while for vestibular functions, the inner ear
is the only one involved.

9. 1. Pinna/auricle/earlobe – funnels the sound
waves into the ear
2. External auditory canal – passageway of
sound to the middle ear; lined with hair
3. Eardrum/tympanic membrane – transmits
sound from the outer ear to the ossicles
4. Malleus, incus, stapes – three small bones of
the ear
5. Eustachian tube – equalizes the pressure in
the middle ear and the throat

11. 6. Cochlea – organ of hearing; Lt. for “snail
shell”; has Organ of Corti
▪ Scala tympani
▪ Scala vestibuli
▪ Scala media
7. Semicircular canals – three (anterior, lateral,
posterior); for balance
8. Vestibule – central part of the bony labyrinth

12. Malleus  faceplate of stapes (3/4 of the
amplitude of movement)
Surface area of tympanic mem. : 55 sq. mm.
Surface area of stapes: 3.2 sq. mm.
22 TIMES MORE PRESSURE ON THE FLUID.

13.  Reduces the intensity of the sound by as
much as 30-40 decibels
 Latent period of 40-80 ms
 Stapedius – pulls stapes outward
 Tensor tympani muscles – pulls malleus
inward
 Reduce ossicular conduction
 Protect cochlea, mask low-frequency sounds
in the env., and dec. sensitivity to own voice

14. Sound energy  Mechanical energy 
Hydraulic movements  Chemical energy 
Electrical energy  BRAIN
Mechanical Energy: Vibrations of the eardrum
 lever-like action of the ossicles
Hydraulic Energy: Faceplate and oval window
 Organ of Corti

16.  Scala tympani – perilymph
 Scala vestibuli – perilymph
 Scala media – endolymph
 Reissner’s membrane (vestibular membrane) – s.
vestibuli from s. media
 Basilar membrane – s. media from s. tympani;
modiolus (high freq. at oval window, low freq. near
the apex)
 Organ of Corti – contains a series of
electromechanichally sensitive cells, hair cells;
transduces pressure waves to action potentials

17. Tympanic
membrane>malleus>incus>s
tapes>oval window>scala
vestibuli>scala
tympani>basilar
membrane>hair cells
receptors
Impedance matching-ossicular
system reduce distance but
increase the force of
movement by 1.3X about 22X
pressure exerted in the fluid.

18.  The movement of the
basilar membrane
cause the hair cell
stereocilia to bend.
 Stereocilia is
directionally sensitive:
 Upward towards scala
vestibuli: hair cells
depolarized
 Down towards the
scala tympani:hair cell
hyperpolarized

19.  From the bending of
the stereocilia opens
ionic channel>influx of
K.
 Membrane potential
decreased to -50mV
from 60mV(resting
membrane potential)
 Opens the Ca2+
channel

20. Spiral ganglion (cochlear
nerve)> dorsal and ventral
cochlear nerve (acoustic
striae)>superior olivary
nucleus> lateral
lemniscus>nucleus of
lateral lemniscus>inferior
colliculus>medial
geniculate
nucleus>auditory
radiation>heschl gyrus
brodmann 41,42

21.  1st order neuron: located in SPIRAL
GANGLION
 2nd order neuron: dorsal and ventral cochlear
nuclei[form 3 groups of acoustic striae(lateral
lemniscus): ventral striae-most prominent
forms trapeziod body]
 3rd order: superior olives nucleus
 4th order neuron: medial geniculate nucleus

22.  Area 41 and 42
>>Primary auditory area-
anterior part: low frequency
Posterior part:reception of high frequency
 Area 22
>>Secondary auditory area
Interpretation of sound and for association of
auditory inputs.

23.  Superior olivary nucleus- fibers joins ipsi and
contralateral lateral lemnisci. Localization of
sound in space
 Nucleus of lateral lamniscus- send axons on
both epsi and contralateral lemnisci. Aids in
bilateralism by sending axon to the
contralateral side.

24.  Whispered Voice Test
 Ticking Watch Test
 Weber Test
 Rinne Test
 Schwabach Test

33.  Conductive hearing loss
 Neural hearing loss (Nerve deafness)
 Mixed hearing loss

34.  sound vibrations don't go from the air around
a person to the moving bones of the inner ear
 sounds are heard, but they are weak,
muffled, and distorted

35.  auditory nerve, which goes from the inner ear
to the brain, fails to carry the sound
information to the brain
 cause a loss of loudness or a loss of clarity in
sounds.
Mixed hearing loss
combination of conductive and neural
hearing losses

36.  Heredity
 Diseases of the Ear
 Injuries of the Ear

37.  born deaf
 cause is unknown
 something that happened to the mother
during her pregnancy

38.  Ear infections
cause fluid or mucus to build up inside the ear
fluids drain out of the ear or are absorbed into the
body
 Otosclerosis
common cause of hearing loss
hereditary disease in which portions of the middle
ear or inner ear develop growths like bony
sponges
can be in the middle ear, the inner ear, or both
places

39.  Meningitis
inflammation of the membrane(called the
meninges) that surrounds the brain and the spinal
column

40.  Punctures of the Eardrum
a hole in the eardrum, which could be caused by
either injury or disease
 Nerve Damage
result of nerve damage is that the electrical
signals of sounds do not get transmitted from the
ear to the brain

41.  Loud Noises
common cause of deafness is repeated or long-
term exposure to loud noises
often cause moderate to severe hearing loss.

42.  sound-amplifying devices
 to aid people who have a hearing
impairment.

43.  Microphone
 Amplifier
 Receiver/ Speaker
 Battery

44.  picks up sound from the environment
 converts it into an electrical signal, which it
sends to the amplifier.
AMPLIFIER
increases the volume of the sound
and sends it to the receiver

45.  changes the electrical signal back into sound
and sends it into the ear
 those impulses are sent to the brain.
BATTERY
provides power to the hearing aid

46.  design
 technology used to achieve amplification
(i.e., analog vs. digital)
 special features

47.  Directional microphone
 T-coil (Telephone switch)
 Direct audio input
 Feedback suppression

48.  help you converse in noisy environments
 allows sound coming from a specific direction
to be amplified to a greater level
 sound coming from in front of you is
amplified to a greater level than sound from
behind you

49.  allows you to switch from the normal
microphone setting to a "T-coil" setting to
hear better on the telephone.
Direct audio input
allows you to plug in a remote
microphone or an FM assistive
listening system or connect to other
devices

50.  helps suppress squeals when a hearing aid
gets too close to the phone or has a loose-
fitting earmold

51.  Behind-the-ear (BTE) aids
 "Mini" BTE (or "on-the-ear") aids
 In-the-ear (ITE) aids
 In-the-canal (ITC) aids and completely-in-
the-canal (CIC) aids

53.  contained in a small plastic case that rests
behind the ear
 case is connected to an earmold or an
earpiece by a piece of clear tubing
 often chosen for young children because it
can accommodate various earmold types
 can help with all types of hearing loss, from
mild to profound
 Sound travels from the earmold into the ear

54.  fits behind/on the ear, but is smaller
 very thin, almost invisible tube is used to
connect the aid to the ear canal
 allow not only reduced occlusion or "plugged
up" sensations in the ear canal
 mild hearing loss who can still hear low- and
mid-frequency sounds

55.  contained in a shell that fills in the outer part
of the ear
 mild to severe hearing loss
 it can accommodate directional microphones
and other added features

56.  contained in tiny cases that fit partly or
completely into the ear canal
 smallest hearing aids available
 In-the-canal (ITC) aids
 works only for mild to moderate hearing loss
 users sometimes experience feedback noise
with this type of hearing aid because the
microphone and receiver sit close together

57.  Completely-in-the-canal (CIC)
 appropriate for mild to moderate hearing
loss, and it's even smaller than the ITC
hearing aid
 barely visible

58.  Analog hearing aids
 Digital hearing aids

59.  aids amplify sounds
 amplify all sounds equally
Digital hearing aids
contain a computer chip
analyzes the sound based on the
person's hearing loss and listening
situation
adjusts for feedback

60.  Young, P.A., Young,P.H.,&Tolbert,D. (2008).
Basic clinical neuroscience. (2 nd ed.).
USA:Lippincott Wlliams and Wilkins
 Hall, J.E., (2010). Guyton and Hall Textbook of
Medical Physiology. (12th ed.).
 Ganong,William F.(2006).Review of Medical
Physiology 23rd edition.San
Francisco,California:Lange Medical
Publications

61.  http://health.howstuffworks.com/medicine/
modern-technology/hearing-aid3.htm
 http://science.jrank.org/pages/3242/Hearing.
html
 http://www.fda.gov/MedicalDevices/Products
andMedicalProcedures/HomeHealthandCons
umer/ConsumerProducts/HearingAids/ucm18
1470.html