Final Exam

Question 1

Speed of Sound

Answer 1

1130 ft/sec or 344 m/sec

Question 2

Octave

Answer 2

Any two frequencies that are a multiple of 2 apart.

Question 3

Octave Band

Answer 3

All frequencies within an octave.

Question 4

Harmonics

Answer 4

Integer multiples of any given primary frequency.

Question 5

Frequency Spectrum

Answer 5

The way a nonmusical sound’s intensity is distributed across frequencies and octaves.

Question 6

Energy=

Answer 6

=intensity (W/㎡) * time of exposure

Question 7

Anechoic Chamber

Answer 7

A room without echoes that has no reverberant field.

Question 8

Phon

Answer 8

Measure of perceived loudness.

Question 9

Conductive Hearing Loss

Answer 9

Hearing loss caused by lesions that are usually treatable in the outer and/or middle ear.

Question 10

Sensory Hearing Loss

Answer 10

Hearing loss that tends to increase with frequency. Cause is within the inner ear and is usually not treatable.

Question 11

Neural Hearing Loss

Answer 11

Hearing loss caused in the auditory or 8th cranial nerve.

Question 12

Presbycusis

Answer 12

Age-related hearing loss.

Question 13

Equation to Add Equal Noises

Answer 13

dBᵪ=dB₁+(10 log x)

Question 14

Equation to Add Unequal Noises

Answer 14

dBᵪ=10 log Σ 10^(dB/10)

Question 15

Equation to Go from a to x Equal Sources

Answer 15

dBᵪ=dBₐ+10 log (x/a)

Question 16

The incidence of NIHL depends upon what four factors?

Answer 16

The intensity of noise exposure
Its spectral frequency distribution
The duration of the noise exposure
The definition of impaired hearing

Question 17

Generic Noise Exposure TIme Limit Equation

Answer 17

time = 8/2^[(dBA-8TWA limit)/(exchange rate)]

Question 18

OSHA Action Level for Noise

Answer 18

85 dBA

Question 19

Lower Threshold for Noise

Answer 19

80 dBA

Question 20

Dose=

Answer 20

=Intensity*Time

Question 21

LAVG

Answer 21

Average noise exposure

Question 22

Insertion Loss

Answer 22

= dB entering a passage - dB exiting a passage

Question 23

Lagging

Answer 23

Two-layered covering applied directly to the outer surface of a source.

Question 24

Transmission Loss=

Answer 24

=10 log Σ Sᵢ - 10 log [Σ Sᵢ*10^(-TLᵢ/10)]

Question 25

Silencer

Answer 25

Straight passageway lined with a noise absorbent material.

Question 26

Snubber

Answer 26

Lined passageway with a deflected path.

Question 27

Dissipative Muffler

Answer 27

A lined wide-spot in a duct

Question 28

Reactive Muffler

Answer 28

More effective muffler over a selected frequency range.

Question 29

Barrier

Answer 29

Free-standing wall like a partition

Question 30

Shield

Answer 30

Small barrier (often a clear material for only one person

Question 31

Required NRR Equation

Answer 31

Required NRR =measured dBA - dBA limit+7

Question 32

X-rms=

Answer 32

=0.707x^^

Question 33

Hysteresis

Answer 33

The phenomenon in which the value of a physical property lags behind changes in the effect causing it.

Question 34

Dominant Frequency of Vibrating Tool=

Answer 34

=RPM/60

Question 35

Electromagnetic Radiation

Answer 35

Propagation or transfer of energy through space and matter by time-varying electric and magnetic fields.

Question 36

12.4 eV

Answer 36

Break point between ionizing and non-ionizing radiation.

Question 37

Continuous Wave Laser

Answer 37

Lasers that produce a constant supply of laser light for ≥0.25 seconds.

Question 38

Alpha Particle

Answer 38

He nucleus

Question 39

Beta Particle

Answer 39

e⁻