Noise and Vibration

Question 1

Sound

Answer 1

Rapid pressure variations

Question 2

Frequency

Answer 2

Cycles per second (Hz)

Question 3

Wavelength

Answer 3

Unit length per cycle

Question 4

Velocity

Answer 4

Frequency x Wavelength

Question 5

Components of outer ear

Answer 5

Pinna, ear canal, ear drum

Question 6

Components of middle ear

Answer 6

Malleus, incus, stapes

Question 7

Components of inner ear

Answer 7

Cochlea and organ of corti

Question 8

Speech frequencies

Answer 8

250 - 3000 Hz

Question 9

Conductive hearing loss

Answer 9

Impairment of sound transmission due to ear wax, damaged ear drum, etc.

Question 10

Sensorineural hearing loss

Answer 10

Impairment of nerve pathway

Question 11

Presbycusis

Answer 11

Hearing loss related to aging

Question 12

Doubling distance

Answer 12

Reduction of SPL by 6 dB in free field with no interference

Question 13

Sound pressure level

Answer 13

Root mean square average, 20 log p/p0 (where p0 = 20 udB)

Question 14

SPL and distance

Answer 14

SPL2 = SPL1 + 20 log10 (d1/d2)

Question 15

Simple rule for adding sound

Answer 15

1-3-9, 3-2-1

Question 16

5 dB exchange rate (OSHA)

Answer 16

Every 5 dB, cut exposure time by half

Question 17

3 dB exchange rate (ACGIH)

Answer 17

Every 3 dB, cut exposure time by half

Question 18

Sound level survey

Answer 18

Area measurement, equipment/source measurements

Question 19

Octave band analysis

Answer 19

Measures a range of frequencies, upper band 2x that of lower band

Question 20

1/3 octave band analysis

Answer 20

Narrower range of octave bands

Question 21

Continuous noise

Answer 21

Intervals <1 sec

Question 22

Source noise control

Answer 22

Dampeners, enclosures, mounts, fans

Question 23

Path noise control

Answer 23

Acoustical tile, floor tile, distance, barriers

Question 24

Individual noise control

Answer 24

Enclosure, hearing protection

Question 25

When to implement HCP?

Answer 25

When exposure exceeds 85 dB in an 8 hour TWA

Question 26

Elements of HCP

Answer 26

Monitoring, audiometry, HP, training, access to info, record keeping

Question 27

Frequency of audiometry

Answer 27

Baseline within first 6 months, annual after that

Question 28

Standard threshold shift

Answer 28

10 dB at 2k, 3k, 4 kHz

Question 29

Revised baseline

Answer 29

Annual may replace baseline if STS is persistent or shows significant improvement over baseline

Question 30

HP required when

Answer 30

Exposure is above 90 dB and admin/eng controls are not feasible

Above AL and no audiogram/STS is experienced

Question 31

Components of training?

Answer 31

Annual, effects of noise on hearing, audiometric testing/procedures, HP info

Question 32

Reqs for record keeping

Answer 32

Exposure measurements for two years, audiometric test records for duration of employment

Question 33

3 components of a vibrating system

Answer 33

Mass, elasticity, damping

Question 34

4 vibration parameters

Answer 34

Displacement, velocity, acceleration, frequency

Question 35

Vibration control

Answer 35

Driving frequency > natural frequency

Question 36

Effects of vibration on the body

Answer 36

Injury, fatigue, annoyance/comfort, interference with duties

Question 37

Whole body vibration TLV basis

Answer 37

Back pain and injury, vehicle operation

Question 38

WBV critical frequencies for longitudinal/transverse

Answer 38

Longitudinal: 3-8 Hz
Transverse: 1-80 Hz

Question 39

WBV measurement

Answer 39

3 accelerometers on long/trans axes

Question 40

WBV controls

Answer 40

Suspended seats, maintenance to reduce vibrations, body support

Question 41

HAV controls

Answer 41

Antivibration tools & gloves, work practices, medical surveillance