The loudness of a sound is a general term that describes whether a sound seems loud or soft (quiet) to the listener.
The amplitude (A) is a precise scientific definition that we use to describe the size of the vibrations. It is a measure of how much the air is disturbed by the sound wave. This is shown on the diagrams below.
The pitch of a note is a general description that tells us whether the note is low or high. Low pitched notes have waves that are long while high pitched notes have waves that are short.
The frequency of the sound is a precise scientific that we use to describe the rate of vibration of a wave such as sound. This is shown on the diagrams below. The frequency of a note is measured in Hertz (Hz). A vibration with a frequency of 1 Hz means that it is vibrating once every second.
