Some taxes are inadvertently hidden, but others are consciously designed that way to disguise the cost of government. Itâs easy to see why: the total U.S. tax burden is equal to 56 percent of annual personal consumption spending.
Thus, the volume is proportional to the amplitude of the sound wave. The frequency of a sound wave is perceived as pitch. Humans can detect pitches within the acoustic range of 20 to 20,000 Hz, but we can't detect ultrasound or infrasound.
The derived SI unit for frequency is hertz (Hz) The common metric multipliers are: kilohertz (kHz) = 1,000 Hz Megahertz (MHz) = 1,000,000 Hz and Gigahertz (GHz) = 1,00 â¦ 0,000,000 Hz. 15 people found this useful. Pitch and frequency both are measured in simple hertz.