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:

    “Mine be a cot beside the hill;
    A bee-hive’s hum shall soothe my ear;
    A willowy brook, that turns a mill,
    With many a fall shall linger near.”
    —Samuel Rogers (1763–1855)