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 Pitch of a sound depends upon the speed of the vibrations causing it. This is called the frequency. The frequency of a sound is measured in Hertz (Hz) after the German sci â¦ entist Heinrich Rudolf Hertz(1857-1894)  1 Hertz = 1 Vibration Per Second. 3 people found this useful.