Telephone handsets are devices commonly used to listen to telephone voice transmissions and to speak into the telephone. A telephone handset typically has a handset casing that houses a transceiver
to allow communication between two points. Handsets come in a variety of shapes and sizes. Telephone handsets include an extraordinary number of components in a relatively confined space. The handset includes a microphone
unit, a speaker
unit, a dialing system, various circuitry including suppressing circuits, and a variety of related interconnecting components. A telephone handset typically comprises an elongate housing which defines a cavity in which a first converter such as a microphone is arranged at one end for converting received acoustic signals into an electrical signal and a second converter such as a speaker is arranged at another end for converting received electrical signals into an audible acoustic signal. Generally the speaker and the microphone are on the same side of the handset. The speaker is normally towards the top end of the handset. The microphone is normally towards the bottom end of the handset. The fronts of handsets frequently have pushbuttons for dialing telephone numbers and for other functions. A corded telephone handset has a main connector
which includes various components such as the signal terminals, battery terminals, DC plug terminals, and circuit boardlocks. The phone is generally connected, by means of a telephone line, to an exchange which supplies the energy necessary to operate the telephone. Telephone cords are used to connect a telephone to either a wall terminal or its handset and typically consist of pairs of insulated copper wires, such as 2, 4 and 8 wires that are commonly arranged in twisted pairs. Each end of the telephone cord fitted with a modular telephone plug to facilitate attachment to a jack hole of a socket either in the telephone or on the wall terminal.