MAGNITUDE

(click on the capital letter for your answer)

1. The decibel is a unit of the measurement of  _________.

A. amplitude
B. intensity
C. loudness
D. intensity level

2. The difference between intensities of 1 watt/m2 and 10-4 w/m2, a difference of 104 or 10,000, is _________.

A. 4 dB
B. 10 dB
C. 40 dB
D. 100 dB

3. Two sound sources of equal intensity when combined under ideal conditions raise the overall sound level by _______, whereas doubling the amplitude of one source raises the level by _______.

First blank
A. 1 dB
B. 3 dB C. 6 dB
D.10 dB
Second blank
A. 1 dB
B. 3 dB
C. 6 dB D. 10 dB

4. Normal conversation is typically in the range of _________, whereas trucks, subways and motorcycles are typically in the range of ________.

First blank
A. 30 dB
B. 60 dB C. 90-100 dB
D. 120-130 dB
Second blank
A. 30 dB
B. 60 dB
C. 90-100 dB D. 120-130 dB

5. The reference level of 0 dB denotes the threshold of hearing and has the same meaning as the reference level commonly found on a level meter for audio signals. T or F.

6. When a particle experiences maximum displacement from its average or rest position due to a vibration, its velocity and the pressure exerted on the surrounding medium are both __________.

A. zero
B. at a maximum
C. at a minimum or negative
D. 0.707 the maximum value

7. A sound level meter reacts to and therefore measures changes in  ___________.

A. loudness
B. intensity
C. sound pressure
D. power

8. SPL may be measured in dBA. T or F

9. The A weighting network on a sound level meter discriminates against low frequency sounds in the same way the ear does at both low and high sound intensity levels. T or F

10. A change of hearing sensitivity due to noise exposure is called  _______.

A. attenuation
B. masking
C. damping
D. TTS

11. The ear is most sensitive in the frequency range of ________.

A. 20 Hz - 2 kHz
B. 100 Hz - 1000 Hz
C. 1 kHz - 4 kHz
D. 10 kHz - 100 kHz

12. Reduction of the dynamic range of an audio signal is called __________.

A. attenuation
B. compression
C. threshold shift
D. enveloping

13. The envelope of a sound is its variation of amplitude in time. T or F

14. The part of the envelope containing information which is the most important for the identification of how the sound source was set in motion is its attack transients. T or F

15. The curves of equal loudness connect points whose loudness is equal; all such points have the same value in units of  __________.

A. Leq
B. dB
C. LA
D. phons

16. Which is a unit of loudness?

A. L10
B. dB
C. SPL
D. sones

17. Which term does not correspond to the temporal dimension of music?

A. dynamics
B. tempo
C. beat
D. metre

For the following questions, use the Handbook links to solve the problem:

18. Using the chart in Inverse Square Law, calculate the corrected level for the distances shown below for a measured level of 70 dB at 20 feet.

A. 5 feet
B. 50 feet

19. Using the chart for Sound Pressure Level, calculate the following summations:

A. 60 dB + 62 dB = _______.
B. 55 dB + 60 dB = ________.
C. 50 dB + 57 dB + 60 dB = _________.

20. Using the chart for Phons, determine the SPL of a 60 Hz tone which has the same loudness as a 1kHz tone which has a loudness of 40 phons: A. ________.  What would be equivalent SPL for a 4 kHz tone? B. ______.



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