Lecture 15 - Human Factors 3

Question 1

_______ = sound pressure perceived as loudness.

Answer 1

amplitude

Question 2

_______ = cycles per second perceived as pitch.

Answer 2

frequency

Question 3

What is the eardrum also known as?

Answer 3

Tympanic membrane

Question 4

An ________ ______ runs from the beginning to the end of the cochlea, splitting it into an upper and lower part. This is called the ?

Answer 4

elastic partition; basilar membrane

Question 5

Bending cause channels, which are on the tips of the _____ to open up.

Answer 5

stereocilia

Question 6

High frequencies cause vibrations at the _______ of the cochlea, and low frequency vibrations cause vibrations at the _______.

Answer 6

base;apex

Question 7

Sound intensity is also known as ______ intensity, and it is defined as the _____ power per unit area.

Answer 7

acoustic; sound

Question 8

What is the SI unit of sound intensity?

Answer 8

W/m2

Question 9

It is common to express the sound intensity using a logarithmic scale known as the _________ scale.

Answer 9

decibel

Question 10

The dB is a ________ way of describing a ratio.

Answer 10

logarithmic

Question 11

The dB scale and the intensity values are _______ measures of sound.

Answer 11

objective

Question 12

Sound with equal intensities but different _______ are perceived by the same person to have unequal loudness.

Answer 12

frequencies

Question 13

A 60dB sound with a frequency of 1000Hz sounds (louder/softer) than a 60dB sound with a frequency of 500Hz.

Answer 13

louder

Question 14

A ______ is used to indicate an individuals perception of loudness.

Answer 14

phon

Question 15

______ and ______ are used to indicate an individual perception of loudness.

Answer 15

phons; sones

Question 16

What does sones tell us that phons don’t?

Answer 16

how much louder one sound is than another

Question 17

Psychophysical scale of sound is an interaction between what two things?

Answer 17

Amplitude and frequency

Question 18

What is the range we’re most sensitive to tones between?

Answer 18

1000-4000Hz

Question 19

Hearing threshold elevation at high frequencies is known as?

Answer 19

Presbycusis

Question 20

What does the audible spectrum decrease to with age?

Answer 20

50-8000Hz

Question 21

Noice-induced hearing loss is caused by damage to what?

Answer 21

structures in inner ear

Question 22

What is one of the most common work-related illnesses in the US?

Answer 22

NIHL

Question 23

Long or repeated exposure to sounds at or above ____ dB can cause hearing loss.

Answer 23

85

Question 24

What is most NIHL caused by?

Answer 24

Damage and eventual death of hair cells

Question 25

Human hair cells don't grow back (T/F)/

Answer 25

True

Question 26

NIOSH recommends that every increase by 3dBA ______ the amount of noise and _______ the recommended exposure time.

Answer 26

doubles; halves

Question 27

Whats the most common construction trade to have NIHL?

Answer 27

Welders (79.5%)

Question 28

_______ has been isolated as one of the highest problematic areas for NIHL in Canada.

Answer 28

Carpentry

Question 29

The average ___ year old carpenter has the ears of a ___ year old person who has not been exposed to noise.

Answer 29

25;50

Question 30

Loud noise exposure can also cause ______; a ringing, buzzing or roaring in the head when no external noise is present.

Answer 30

tinnitus

Question 31

Tinnitus can be caused by damage to improper transmission through sensory _______ or pathway to the ______.

Answer 31

organs; brain

Question 32

Sometimes exposure to impulse or continuous loud noise causes a temporary hearing loss that disappears ____ to ____ hours later. What is this called?

Answer 32

16;48; temporary threshold shift or auditory fatigue

Question 33

In intense noise, displacement of basilar membrane of maximum vibration is large, and hair cells are ______ by considerable force.

Answer 33

bent

Question 34

Overstimulation leads to temporary ________ or hair cells.

Answer 34

paralysis

Question 35

Temporary threshold shift (TTS) is usually measured ___ minutes following exposure to avoid recovery.

Answer 35

2

Question 36

TTS usually experienced at frequencies high than the exposure frequency, usually ______Hz.

Answer 36

4000

Question 37

________ noise causes raised levels of cortisol and other stress hormones.

Answer 37

chronic

Question 38

There is a _____ correlation between long term noise exposure above 67-70 dB and hypertension.

Answer 38

weak

Question 39

Noise levels of _____ dB(A) at night may increase the risk of myocardial infarction.

Answer 39

50

Question 40

The vestibular system encodes _______ and _______ acceleration of the head.

Answer 40

linear; rotary

Question 41

The vestibular system senses constant _______ acceleration by earth gravity and thus signals to the brain head movement and position with respect to constant gravitational _______.

Answer 41

linear; acceleration

Question 42

What three things does the vestibular system do?

Answer 42

1. Detect acceleration forces 2. Maintains upright posture/balance 3. Controls eye position relative to head

Question 43

_______ _______ detect angular acceleration in 3 axes.

Answer 43

semicircular canals

Question 44

In semicircular canals, a ____ is embedded in jelly-like material (cupola) is supported by hair cells that bend and fire in response to head rotation.

Answer 44

crista

Question 45

_________ ____ detect linear acceleration.

Answer 45

Vestibular sacs

Question 46

The vestibular sacs (utricle and saccule) are hair cells in jelly like substance that ____ behind when the head moves.

Answer 46

lag

Question 47

________ refers to involuntary movement of the eyes.

Answer 47

Nystagmus

Question 48

What may nystagmus sometimes be accompanied with?

Answer 48

Vertigo

Question 49

Individuals exposed to intense noice may have evidence of vestibular pathology only when there is an _________ hearing loss.

Answer 49

asymmetrical

Question 50

What are the two types of nystagmus?

Answer 50

1. Spontaneous | 2. Positional