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.
Sound: Pitch and Acoustics. This page is a continuation of the page study of the science of sound. An important measurement of sound is the frequency. This is how fast the sound wave is oscillating. This is different than how fast the wave travels through the medium. Frequency is measured in hertz.