Hum (sound)


A hum is a sound made by singing a wordless tone with the mouth completely closed, forcing the sound to emerge from the nose. To hum is to produce such a sound, most often with a melody. It keeps the volume at a low level, so humming is rarely used in musical productions, with some exceptions such as scat singing and vocables. Humming is sometimes used to keep the melody when the singer does not know the lyrics.