telephone, an instrument designed for the simultaneous transmission and reception of the human voice. The telephone is inexpensive, is simple to operate, and offers its users an immediate, personal type of communication that cannot be obtained through any other medium. As a result, it has become the most widely used telecommunications device in the world. Billions of. May 30, 2022 · 5. Attach telephone wire to the old jack. Open the casing, or unscrew the plating, on the old jack. Loosen the screws that secure the red, green, yellow and black telephone wires. As necessary, trim damage from the old wires and strip the insulation from the tips. Strip the insulation from the tips of the new wires, too..