The voltage applied to the cable is directly proportional to the audio signal, overlaid on a ~1 MHz carrier. All you need is a mechanism that transforms those voltages into vibrations or pressure waves. Presumably, since it seems to happen only when he&#x27;s striking an arc, it&#x27;s related to the local heating of the air in the gap ... But I guess it could be electromagnetically induced vibrations of the cable or the tower structure ...<p>There used to be stories, not entirely urban legend, of people who lived close to AM towers hearing the station in the wiring of their home, or in their dental appliances. Not impossible, considering that many AM stations broadcast with 50kW of power (like the one in this video) and can be received across a large swath of the country.