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.
Hertz is the standard measure of the frequency of oscillations in a wave motion. The frequency is 1 Hz when one oscillation occurs in one second. When 1000 oscillations occur in one second, the frequency is 1000 Hz, or 1 kHz (kilohertz). Pitch names start from the C of the subcontraoctave (C 2). The frequency of the C2 is approximately 16 Hz (oscillations per second).