Hertz

Hertz is a unit of frequency (of change in state or cycle in a sound wave, alternating current, or other cyclical waveform) of one cycle per second. It replaces the earlier term of "cycle per second (cps)."In acoustic sound, the range of human hearing is from 0 Hz to roughly 20 kHz (depending on many factors, including age and how loud the drummer in your high school rock band played!). The pitch of Middle C on a piano is 263 Hz. Hertz is also used frequently when describing the individual bands of an audio equalizer. To make that Middle C louder, you could boost other frequencies to around 263 Hz with an equalizer. The unit of measure is named after Heinrich Hertz, German physicist.