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.
Pitch is how high or low we hear a sound to be. If the frequency is higher, the pitch is higher. The unit of frequency is hertz. Ghz, or gigahertz, also can be used to measure frequencies. We can hear all the way up to 20,000 hertz! To conclude, the higher the frequency, the higher the pitch.