Mains Hum

Mains hum, electric hum, or power line hum is an audible oscillation of alternating current at the frequency of the mains electricity, which is usually 50 Hz or 60 Hz, depending on the local power line frequency. The sound often has heavy harmonic content.

Read more about Mains Hum:  Causes of Electric Hum, Prevention, Tone, In Music, In Audio Systems, In Forensics

Famous quotes containing the word hum:

    One’s condition on marijuana is always existential. One can feel the importance of each moment and how it is changing one. One feels one’s being, one becomes aware of the enormous apparatus of nothingness—the hum of a hi-fi set, the emptiness of a pointless interruption, one becomes aware of the war between each of us, how the nothingness in each of us seeks to attack the being of others, how our being in turn is attacked by the nothingness in others.
    Norman Mailer (b. 1923)