The frequency of the lowest sound that the normal human ear can perceive ranges between 16 and 20 hertz.

a. True

b. False

that is true.

also here is some more info.

The human is is not sensitive to sound intensity (energy), but the human ear is sensitive to sound pressure or to sound pressure level (SPL). It is ranging from 20 micro pascals to 150 pascals, that is a SPL of 0 dB (threshold of hearing) to 137.5 dB (threshold of pain). Scroll down to related links and look at "Table of Sound Levels and corresponding Sound Pressure".