Speech Mech Chapter 9 Part 1

Question 1

Audition

Answer 1

The process associated with hearing

Question 2

The ear is

Answer 2

an energy transducer; it changes acoustic energy into electrochemical energy

Question 3

Structures of the ear

Answer 3

Outer, middle, inner ear, auditory pathways

Question 4

The pinna (auricle)
Prominence referred to

Answer 4

“the ear”

Question 5

Structure provided

Answer 5

by a cartilaginous framework
A Collector of sound that is processed in the middle ear and cochlea

Question 6

Landmarks of pinna

Answer 6

•Helix (curled margin) and auricular tubercle (posterior bulge on the helix)
•Concha- entrance to ear canal

Question 7

Concha: aids in

Answer 7

localizing the sound sources that come from the front, below and above the head

Question 8

Concha helps

Answer 8

to funnel sounds directed to it to the external auditory canal

Question 9

The auricle is more efficient at delivering

Answer 9

high frequency sounds than low frequency

Question 10

The auricle helps

Answer 10

in localization of sounds delivered to the head

Question 11

Microtia

Answer 11

small auricle

Question 12

Anotia

Answer 12

refers to complete absence of the pinna

Question 13

Pre-auricular tags

Answer 13

are prominences that form prenatally anterior to the pinna

Question 14

External auditory meatus (EAM) is the

Answer 14

External ear canal
and is 7 mm in diameter and 2.5 cm long

Question 15

External auditory meatus (EAM)Terminates at the

Answer 15

tympanic membrane
* Two-thirds of ear canal housed in bone (osseous
portion)
* One-third of ear canal composed of cartilaginous
parts

Question 16

Resonating cavity that contributes to hearing

Answer 16

Determine resonant frequency

Question 17

Outer third- line with hair cells and cerum (ear
wax)

Answer 17

protects by trapping dirt and insects

Question 18

The two portions of the EAC meet
together at the

Answer 18

osseocartilaginous
junction

Question 19

The condyle lies just below this junction
and when the mandible (jawbone)
overrides

Answer 19

its normal position, the
condyle will press into the junction
causing pain
Referred to as TMJ or Temporomandibular Joint
disorder
Produces a referred pain in the ear referred to as
otalgia (ear pain)

Question 20

Otitis externa

Answer 20

refers to
inflammation of the skin of the
external ear.

Question 21

Cerumen

Answer 21

(ear wax) impaction

Question 22

meatal atresia

Answer 22

absence of the
external auditory meatus

Question 23

Tympanic Membrane (TM) Also known as the

Answer 23

eardrum

Question 24

Tympanic Membrane Separates

Answer 24

the middle ear from the
outer ear

Question 25

Tympanic Membrane is

Answer 25

Oval shaped, 10 mm in diameter
* Thin three layered sheets of tissue
* Landmarks

Question 26

Umbo

Answer 26

point of attachment for malleus,
middle ear bone- location is cone of light
(reflects light from otoscope)

Question 27

The TM marks the border between the
outer and middle ear
Constructed of 3 layers

Answer 27

outer middle and inner

Question 28

Outer layer

Answer 28

visible from the EAC

Question 29

Middle layer:

Answer 29

tough, fibrous, connective tissue that
contributes the ability of the TM to vibrate to
sounds

Question 30

Inner Layer:

Answer 30

lined with mucous membrane which is
consistent with the middle ear

Question 31

The TM is very rich in

Answer 31

blood supply (vascular

Question 32

Tympanic Membrane Responsible for

Answer 32

initiating
mechanical impedance-matching
process of middle ear

Question 33

First layer

Answer 33

outer (cuticular) layer

Question 34

Second layer

Answer 34

Intermittent (fibrous) layer

Question 35

Third layer

Answer 35

inner (mucous) layer

Question 36

Middle Ear Impedance Matcher

Answer 36

The area of the TM is 17 times that of
the oval window
– This allows for a sound pressure increase
in the middle ear to transfer the pressure
to the inner ear via the oval window
– The increase is needed due to a transfer
of sound from air to fluid in the inner ear

Question 37

The TM is NOT

Answer 37

100% efficient as an
impedance matcher

Question 38

Middle Ear Impedance Matcher
Increased

Answer 38

pressure and the lever action
of the malleus result in a pressure
increase of 23 times that of an airborne
transmission alone
– This is approximately a 30 dB increase
– A 28 dB loss would result due to the air
to fluid impedance mismatch without the
ossicles

Question 39

middle ear Contains

Answer 39

the three smallest bones of
the body
* Bones of middle ear called ossicles

Question 40

Ossicular chain: collective name for
ossicles

Answer 40

Malleus
– Incus
– Stapes
* Transmit acoustic energy from TM

Question 41

Malleus

Answer 41

Largest of the ossicles
* Nine mm long and weighs only 25 mg
– Provides point of attachment with tympanic
membrane
– Bulk of bone is the head or caput

Question 42

The manubrium (handle) of the malleus is

Answer 42

embedded in the middle (fibrous) layer of the
TM and extends to the center of the TM of the
area of greatest retraction (umbo)

Question 43

Incus

Answer 43

Shaped like an anvil
– Weighs 30 mg and is around 7 mm long
– Provides intermediate link of ossicular chain
– Incus and malleus articulate by means of a
saddle joint

Question 44

Stapes (stirrup)

Answer 44

Third bone of ossicular chain
– Weighs 4 mg with an area of 3.5 mm2
– Helps to transmit sound vibrations from
eardrum to oval window
– Articulation of the incus and stapes of ball
and socket type

Question 45

Ossicular chain is held

Answer 45

in place by
ligaments