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.
The audio spectrum is the audible frequency range at which humans can hear. The range spans from 20 Hz to 20,000 Hz and can be effectively broken down into seven different frequency bands, with each having a different impact on the total sound.idrange: 500 Hz to 2 kHz. The midrange determines how prominent an instrument is in the mix. Boosting around 1000 Hz can give instruments a horn like quality. Excess output at this range can sound tinny and may cause ear fatigue.