21.
The beginning or starting point on the relative scale of noise levels is about the
level of the weakest sound that can be heard by a person with very good hearing
in an extremely quiet environment. The word for this is _____________and is
expressed as ________________.
a. Decibel (dB or db); "0 dB."
b. DB(A); "0 dB."
c.
dB(P); "0 dB."
d. DB; "0 dB."
22.
A dB(P):
a. Is the frequency and intensity sound level?
b. Expresses the peak sound pressure of impulse noise.
c.
Is usually the sound pressure expressed in micropascals.
d. Is used for sound test frequencies above 10 micropascals.
23.
Which item in Table 3-1 has a peak sound pressure of impulse noise at 94 dB(A)?
a. Whisper.
b. Howitzer.
c.
d. Printing plant.
24.
If over an extended period of time, ears are exposed to excessive noise, what
happens to the individual's inner ear?
a. The hair and hair cells activate, causing hearing injury or destruction.
b. Injury to the organ of Corti usually leads to permanent loss of hearing.
c.
Depending upon the duration of the exposure to excessive noise, hearing loss
may be only temporary in nature.
d. All of the above.
MD0165
3-34