Actually, internal components, processors, etc, work outside the typical analog band of 20Hz to 20KHz. Digital circuits work between 80KHz up to GHz pending processor design. The PE, same as all other types of parallel filters, address the harmonics above 60Hz that effect this type of circuit. At the same time, the PE also effects the analog band via enhancing common mode rejection inside the house wiring. In a typical application, the PE provides common mode rejection, power factor correction, RF/EM filtering, and component isolation. All parallel filters offer the same benefit, but to my knowledge, the PE has the widest bandwidth of any parallel filter on the market.
Alan Maher