Sound and the Ear

Question 1

acoustics

Answer 1

the study of sound

Question 2

3 prerequisites for sound production

Answer 2

1. force
2. a vibrating object that generates a pressure wave
3. air

Question 3

force

Answer 3

source of energy

Question 4

air

Answer 4

medium of transmission

Question 5

what is sound?

Answer 5

vibrations carried through the air in the form of pressure waves

Question 6

sound waves are represented as…

Answer 6

sine waves

Question 7

sine waves

Answer 7

air molecules are moving along the same axis as a function of time

Question 8

sound is caused by…

Answer 8

vibrations of air molecules
- air molecules are set into vibration which cause them to shove together and pull apart

Question 9

compression

Answer 9

when the air molecules are shoved together

Question 10

rarefaction

Answer 10

when the air molecules and pulled apart

Question 11

sound waves pass through air as a…

Answer 11

function of time

Question 12

1 cycle equals

Answer 12

1 compression and 1 rarefaction

Question 13

cycles per second (cps)

Answer 13

• how many cycles are occurring per second
• also means frequency

Question 14

frequency

Answer 14

number of complete cycles of vibration that occur per unit of time measured in Hertz (Hz)

Question 15

pitch

Answer 15

perception of frequency

Question 16

determining frequency

Answer 16

counting the number of cycles per second

Question 17

wavelength

Answer 17

the distance between waveforms

Question 18

high frequency =

Answer 18

more cycles per second

Question 19

low frequency =

Answer 19

fewer cycles per second

Question 20

if the length of the waveform decreases (shortens)…

Answer 20

frequency increases (higher Hz)

Question 21

if the length of the waveform increases (widens)…

Answer 21

frequency decreases (lower Hz)

Question 22

pascal (Pa)

Answer 22

• unit of measurement for sound pressure
• linear measure scale

Question 23

human hearing sensitivity ranges from…

Answer 23

0.0002 dynes/cm(2) to 2000 dynes/cm(2)

Question 24

decibel (dB)

Answer 24

• uses a logarithmic scale to make human hearing sound measurement manageable
• non-linear
• measure of intensity

Question 25

dB is a non-linear measurement meaning...

Answer 25

0 dB does not mean 0 sound

Question 26

intensity

Answer 26

physical property of an acoustic signal

Question 27

loudness

Answer 27

subjective, perception

Question 28

dB will have a suffix attached indicating...

Answer 28

how it is being used

Question 29

dB SPL

Answer 29

- decibel sound pressure level - calibration, sound measurements

Question 30

dB HL

Answer 30

- decibel hearing level - audiograms

Question 31

dB SL

Answer 31

- decibel sesnation level - intensity above someone's threshold - speech audiometry

Question 32

the human ear is a...

Answer 32

transducer

Question 33

the human ear as a transducer

Answer 33

- changes 1 form of energy to another - acoustic to fluid/electrical

Question 34

sound travels...

Answer 34

through the air and into the outer ear

Question 35

the middle ear is an...

Answer 35

impendence matching transducer that changes energy to fluid

Question 36

pinna is also known as the...

Answer 36

auricle

Question 37

2 parts of the external auditory meatus

Answer 37

1. cartilaginous 2. bony

Question 38

cartilaginous part of the EAM

Answer 38

- outermost portion - contains hair and cerumen

Question 39

body part of the EAM

Answer 39

- innermost portion - extends to temporal bone

Question 40

purpose of the external auditory meatus

Answer 40

- protect tympanic membrane from trauma - act as a tube resonator for efficient sound transfer - maintain temperature and humidity levels - acts as a filter to reduce low frequencies

Question 41

tympanic membrane

Answer 41

concave, disk-like, opaque

Question 42

3 layers of the tympanic membrane

Answer 42

1. skin 2. fibrous connective tissue 3. mucous membrane

Question 43

pars tensa

Answer 43

2/3 of tympanic membrane contains all 3 layers

Question 44

pars flaccida

Answer 44

1/3 of tympanic membrane contain only 2 layers (skin and mucous membrane)

Question 45

ossicles

Answer 45

1. malleus 2. incus 3. stapes

Question 46

malleus

Answer 46

attached to tympanic membrane and incus

Question 47

incus

Answer 47

attached to malleus and stapes

Question 48

stapes

Answer 48

attached to incus and embedded into oval window

Question 49

eustachian tube

Answer 49

connected to the nasopharynx and is at an angle in adults

Question 50

children's eustachian tube is horizontal, resulting in...

Answer 50

higher likelihood of ear infections

Question 51

the eustachian tube is normally...

Answer 51

closed

Question 52

when does the eustachian tube open?

Answer 52

when you yawn, sneeze, or swallow

Question 53

what does the eustachian tube do?

Answer 53

equalizes the air in front of and behind the tympanic membrane

Question 54

stapedius and tensor tympani muscles

Answer 54

- contract in response to an intense sound as a form of protection - averages a 15-20 dB decreases in sound pressure - bilateral respons

Question 55

when the stapedius and tensor tympani muscles contract...

Answer 55

they stiffen the ossicular chain

Question 56

purpose of the inner ear: cochlear

Answer 56

hearing

Question 57

purpose of the inner ear: vestibular portion including semicircular canals

Answer 57

balance

Question 58

purpose of the inner ear

Answer 58

to transduce the mechanical energy delivered from the ME into a form of energy that can be interpreted by the brain (electrochemical energy)

Question 59

auditory labyrinth: cochlea

Answer 59

sensory end organ of hearing

Question 60

vestibular labyrinth consists of...

Answer 60

- semicircular canals - utricle and saccule

Question 61

semicircular canals

Answer 61

sensory end organ of balance

Question 62

utricle and saccule

Answer 62

additional organs of balance

Question 63

cochlear chambers

Answer 63

- scala vestibuli - scala media - scala tympani

Question 64

scala vestibuli

Answer 64

filled with perilymph fluid

Question 65

scala media

Answer 65

- middle most chamber - filled with endolymph fluid

Question 66

scala tympani

Answer 66

filled with perilymph fluid

Question 67

cochlear fluids

Answer 67

- perilymph fluid - endolymph fluid - endocochlear potential

Question 68

perilymph fluid

Answer 68

high sodium, low potassium

Question 69

endolymph fluid

Answer 69

low sodium, high potassium

Question 70

endocochlear potential

Answer 70

opposite potentials help with neurotransmission of sounds

Question 71

basilar membrane

Answer 71

- sits on the floor of the scala media - houses the organ of corti

Question 72

the organ of corti houses our hair cells...

Answer 72

1 row of inner hair cells and 3 rows of outer hair cells

Question 73

why do we lose higher frequencies first?

Answer 73

because they are on the outer portion and are more vulnerable

Question 74

retrocochlear pathway

Answer 74

- beyond the cochlea - 8 nerves and brainstem

Question 75

auditory cortex (temporal lobe)

Answer 75

- Broca's area - Wernicke's area

Question 76

conductive hearing loss

Answer 76

caused by outer and/or middle ear dysfunction

Question 77

sensorineural hearing loss

Answer 77

caused by inner ear dysfunction

Question 78

mixed hearing loss

Answer 78

caused by outer and/or middle and inner ear dysfunction