Nitro-. a combining form or an adjective denoting the presence of niter. Nitro-. a combining form (used also adjectively) designating certain compounds of nitrogen or of its acids, as nitrohydrochloric, nitrocalcite; also, designating the group or radical NO2, or its compounds, as nitrobenzene.
The commonly stated range of human hearing is 20 Hz to 20 kHz. Under ideal laboratory conditions, humans can hear sound as low as 12 Hz and as high as 28 kHz, though the threshold increases sharply at 15 kHz in adults, corresponding to the last auditory channel of the cochlea.
Audible Range of Human Hearing â The average person has a normal hearing range that falls between 20Hz on the low side and approximately 20,000 Hz on the high side.As we age the overall perceivable range of sound decreases especially in the higher frequencies.requency is measured using the Hz symbol meaning Hertz. The chart above shows a total span of frequencies from 20 Hz to 130,000 Hz. Noting that the limitation of the range of human hearing is between 20 Hz and 20,000 Hz one can easily see that frequencies exist outside of our capability to hear them.