Sound Intensity and Human threshold for hearing

[mssweeteypie]

Is it possible to have a negative sound intensity level?
A sound that is below the threshold of human hearing has...

(A) a negative intensity level (in dB).
(B) a negative intensity (in W/m^2 ).
(C) an intensity level of zero.
(D)an intensity level less than 1 dB , but greater than 0.

I think I know the answer but I don't want to guess wrong and lose points.



Does it have to do with anything like I/Io or I=power/area ??


I think the answers is A or B..but I don't see the difference in between dB and W/m^2 i thought they are the same thing.

 

[TVP45]

I think you're confusing yourself. Look at the units in answers A and B and ask yourself how each could physically be negative.

 

[Moetasim]

I can confirm that it is not possible to have a negative sound intensity level. Sound intensity is measured in terms of decibels (dB), which is a logarithmic scale. The human threshold for hearing is around 0 dB, and any sound below this level would have a negative value on the decibel scale. However, this does not mean that the sound has a negative intensity level.

Intensity is a physical quantity that is measured in watts per square meter (W/m^2). It is a measure of the amount of energy that is transferred through a given area in a given time. The human threshold for hearing is around 10^-12 W/m^2. Any sound below this level would have a very low intensity, but it would still be a positive value.

Therefore, the correct answer is C - an intensity level of zero. This means that the sound is below the threshold of human hearing and therefore cannot be heard. It is important to note that the human threshold for hearing can vary from person to person and can also be affected by factors such as age and hearing impairment.