Test Questions with All Verified Solutions.
1. Sound amplification in the outer ear (auditory canal) is affected by:
a. Sound speed
b. Sound pressure
c. Sound amplitude - Correct Answer-b. Sound pressure
2. Prolonged exposure to loud noise can cause permanent damage to:
a. The air conductivity (of the ear)
b. The structure of the eardrum (tympanic membrane)
c. Inner ear - Correct Answer-c. Inner ear
3. The loss of elasticity (stiffening) of the tympanic membrane will result in:
a. Increase of air conductivity
b. Decrease of hearing threshold
c. Decrease in the binaural effect - Correct Answer-b. Decrease of hearing threshold
4. Sound intensity level (dB) and Loudness (phones) will have the same magnitude at the
following frequency:
a. 20 Hz
b. 1000 Hz
c. 20 KHz - Correct Answer-b. 1000 Hz
5. Refer to the equal-loudness curve above. At frequency of 4000 Hz the perceived sound
is:
a. Louder than at 1000 Hz
,b. The same as at 1000 Hz
c. Softer than at 1000 Hz - Correct Answer-a. Louder than at 1000 Hz
6. Sound Intensity Level is proportional to the logarithm of the ratio of incoming to
threshold intensity SIL = 10·Log (I/I0). If intensity is increased by a factor of 100, what is
change in SIL?
a. Increase by a factor of 10 (10 times)
b. Double (2 times)
c. Increase with 20 dB (plus 20dB) - Correct Answer-c. Increase with 20 dB (plus 20dB)
7. The sound intensity level in a room is 20 dB. A TV produces additional intensity level of
60 dB. What is the sound intensity in the room now?
a. 80 dB
b. 40 dB
c. 60 dB - Correct Answer-c. 60 dB
8. Match the physical (objective) with the corresponding psychophysical (subjective)
properties of the sound: (hint: multiple connections are possible)
a. Frequency
b. Intensity
c. Acoustic spectrum
1. Timbre
2. Pitch
3. Loudness - Correct Answer-a. - 2.; b. - 3.; c. - 1.
9. Sound frequency is:
a. Psychophysical property (subjective)
b. Physical property (objective)
,c. Sound is measured in wavelength, and light is measured in frequency - Correct Answer-
b. Physical property (objective)
10. The fundamental harmonic (frequency f0) in a complex sound is characterized by:
a. The lowest frequency and highest amplitude
b. The highest frequency and lowest amplitude
c. The highest frequency and highest amplitude - Correct Answer-a. The lowest frequency
and highest amplitude
11. The speed of sound is calculated by the Newton-Laplace formula √(K/ρ), where K is
the stiffness coefficient, and ρ is the density of the material. If the density of the substance
doubles, the speed of propagating sound wave will:
a. Increase
b. Decrease
c. Depends on the frequency - Correct Answer-b. Decrease
12. What is the speed of sound in air?
a. 330 m/s
b. 900 m/s
c. 1550 m/s - Correct Answer-a. 330 m/s
13. Does absorption of sound and the corresponding penetration depth depend on the
wavelength?
a. No
b. It does. There is less absorption at longer wavelengths, and they propagate deeper
c. It does. There is less absorption at shorter wavelengths, and they propagate deeper -
Correct Answer-b. It does. There is less absorption at longer wavelengths, and they
propagate deeper
14. Is it possible for internal organs to generate sounds that propagate to the skin, and are
audible?
, a. No
b. Yes, organs produce sounds that propagate through the tissues and are audible at the
skin
c. No, organs generate sounds but the waves are absorbed by the tissues and are
inaudible at the skin - Correct Answer-b. Yes, organs produce sounds that propagate
through the tissues and are audible at the skin
15. Noise can be defined as:
a. Intense sound with constant frequency
b. Directed sound waves with low intensity and changing modulation
c. Superposition of random sound vibrations, with frequency and amplitude constantly
changing in time. - Correct Answer-c. Superposition of random sound vibrations, with
frequency and amplitude constantly changing in time.
16. Damping oscillations are:
a. Oscillations with increasing amplitude
b. Oscillations with decreasing amplitude
c. Not related to amplitude - Correct Answer-b. Oscillations with decreasing amplitude
17. If the amplitude of a wave doubles (x2), what would happen to the period?
a. It will double
b. It will be halved
c. There will be no change - Correct Answer-c. There will be no change
18. In which of the following mediums, sound waves cannot propagate?
a. Gases
b. Liquids
c. Vacuum - Correct Answer-c. Vacuum