Turn on, turn off the appliance, low-frequency hum: Listen & Download Turn off the appliance,, Turn on .mp3 Error! Change your browser, please! ⇓ Download Turn on, turn off the appliance, ⚠ Switch ⚠ Electric sparks ⚠ Low frequency rumble ⚠ Electric transformer ⚠ Shoots an electric arc indoors ⚠ Button click ⚠ Small electric motor ⚠ Tesla coil, Electric discharges ⚠ Electrical discharge surge ⚠ Jacob’s ladder, Electric discharges ⚠ Wall switch ⚠ ★★★★★