Now *this* is a speaker phone, conference calling with a rotary dialer, awesome… Popular Science 1948 – “The busy executive can now carry on conversations over the telephone without even lifting a finger to hold it. With the Jordaphone (PSM, Oct. ’45, p. 96), a wartime development of the Jordanoff Corp., he need only transfer the phone from its regular cradle to the special one in the top of the instrument. Here the incoming voice is picked up directly from the phone’s earpiece and amplified through a loudspeaker, eliminating actual wire connections. An ordinary microphone, placed anywhere in the room, transmits the outgoing voice to the mouthpiece.
In addition to freeing the user’s hands, the device permits group conferences by telephone without individual sets (at right, above). An automatic volume control tunes down voices near the microphone and amplifies those at a distance. The 30-inch-high, foot-square console (at left) plugs into any 110-volt outlet.” – Link.