What device can be used to minimize the effect of RF pickup by audio wires connected to stereo speakers, intercom amplifiers, telephones, etc.?

Long audio wires connected to speakers, intercoms, or telephones can easily act as unintended antennas, picking up stray Radio Frequency (RF) energy. A highly effective and simple way to choke off this RF current is by creating a coil around a ferrite core, often called a ferrite choke or ferrite bead. Ferrite cores are magnetic materials that offer high resistance (impedance) to high-frequency RF signals while allowing low-frequency audio signals to pass through unaffected. When the wire is wrapped around the ferrite, it forms a common-mode choke that blocks the RF interference. Other options are incorrect: high-pass filters block audio and pass RF (the opposite of what is needed), attenuators reduce all signal levels, and surge suppressors are for high-voltage power spikes, not RF interference.