DICTA PHONE

an instrument which is made up of an ordinary telephone circuit to which is attached a transmitter sensitive enough to take up the words of persons conversing in the room so that they can be heard and recorded on the telephone. The transmitter is usually small enough so that it can be concealed in some part of the room in which it is used. The dicta phone has been used extensively in recent years to gather evidence by detectives and others. It also has a practical use in the reproduction of sounds in different parts of halls and rooms. It has been installed in the waiting rooms of railway stations where the announcer has his voice megaphoned by telephone receivers located in various parts of the building.