What is the relative highness lowness or sameness of sound?

The relative highness lowness or sameness of sound is called pitch. Pitch is a sound quality that allows the human ear to rank sounds on a scale from low to high. Low pitches have longer sound waves and high pitches have shorter sound waves. The unit for measuring pitch is the hertz (Hz), which represents one cycle per second. The higher the frequency of sound waves, the higher the pitch. Pitch is perceived by the brain and is an important factor in music, speech, and sound effects.