Plastic Shell Equips Phone For Two-Way Listening, 1953

Two persons can share the same telephone with a device patented by Roger Heap of Lyme, Connecticut in 1953.

Simple in design, it consists of a T-shape plastic shell which cups over the receiving end of the phone. The hollow arms transmit the message to listeners at both sides. Heap fashioned the device so that he and Mrs. Heap could join in three-way conversations with their son in Detroit.