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 hertz (symbol: Hz) is a unit of time which measures frequency. Frequency is how often something happens. A frequency of 1 hertz means that something happens once a second.The note Middle C (the C in the middle of the piano) is 262 Hz. This means there are 262 vibrations every second, which is heard as the note Middle C, when that piano key is played.requency is how often something happens. A frequency of 1 hertz means that something happens once a second. The note Middle C (the C in the middle of the piano) is 262 Hz. This means there are 262 vibrations every second, which is heard as the note Middle C, when that piano key is played.