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.
For the sound wave we use Hertz as the unit of measurement where 1 Hertz = 1 vibration/second. Conceptually whenever a wave passes the medium it makes the first particle to which it comes in contact, vibrate. Then this particle vibrates the nearby particle at the same frequency. This is how energy is propagated.