Audio Frequency represents the rate at which a vibration/pressure wave occurs per second and is measured in Hertz (Hz) units. For example, if ten complete pressure waves happen within one second, the frequency would be 10 Hz. The generally accepted standard hearing spectrum for humans is 20 Hz to 20,000 Hz. However, this range reduces for most people as they get older.

The different frequency ranges produce specific types of sounds. For example, low range frequencies produce a bassy sound. We can even feel some very low bass sounds more than we can hear them.

In sound design, understanding how the different frequency ranges can allow for audio adjustments in a project using an Equalizer (EQ.) An EQ is a tool available in many editing and audio software that allows you to adjust various frequency ranges.

Listen to a range of frequencies that humans can hear: