Which of the following are the basic physical acoustical quantities used to…
2024
Which of the following are the basic physical acoustical quantities used to characterize sound or noise?
A. Pressure
B. Mass
C. Power
D. Quality
E. Intensity
Answer: C. ACE — ConceptPhysical acoustics distinguishes three basic quantities used to describe and measure sound or noise: sound pressure, sound power, and sound intensity.…
- A.
ABC
- B.
BDE
- C.
ACE
- D.
ACDE
Show answer & explanation
Correct answer: C
Concept
Physical acoustics distinguishes three basic quantities used to describe and measure sound or noise: sound pressure, sound power, and sound intensity.
Sound pressure describes pressure fluctuations at a point, sound power is the acoustic energy emitted by a source per unit time, and sound intensity is the acoustic power passing through unit area in a specified direction.
Application
Classify each listed term by what it represents:
Statement | Category and meaning |
|---|---|
Pressure | Physical acoustical quantity; the local pressure fluctuation produced by the wave. |
Mass | Property of matter; it is not itself a sound or noise level quantity. |
Power | Physical acoustical quantity; acoustic energy emitted by the source per unit time. |
Quality | Perceptual attribute, often associated with timbre; it is not one of these physical noise quantities. |
Intensity | Physical acoustical quantity; acoustic power transmitted per unit area. |
Cross-check and contrast
ABC includes mass, an amount-of-matter property, along with pressure and power.
BDE includes mass and perceptual quality, while omitting pressure and power.
ACDE adds perceptual quality to the three physical acoustical quantities.
Therefore, the required statements are A, C, and E, so the combination is ACE.