Corded telephone

A telephone set permits the transportation of speech over a distance by means of electric signals. At the transmitting end, the telephone set carries out a transformation of acoustic signals into electric signals. At the receiving end, the telephone set carries out the transformation of the electric signals into acoustic signals. A telephone is generally connected, by means of a telephone line, to an exchange which supplies the energy necessary to operate the telephone. In particular, the exchange constantly transmits a direct-current supply voltage on the telephone line. A telephone set generally has a main body and a handset. The handset is connected to the main body by a cord. The main body is usually provided with a recessed area on which a hook switch is disposed. When the handset is not in use, it is seated on the recessed area of the main body and the hook switch is opened to disconnect the telephone circuit. To use the telephone, the handset is picked up from the main body and the hook switch is activated to connect the telephone circuit so that a dialing can be started. Telephone sets typically include a microphone, an earpiece, a keypad and a loudspeaker. The microphone converts an acoustic input signal into an electric input signal. The earpiece converts an electric output signal into an acoustic output signal. A multi-functional telephone set usually includes two additional operating modes, namely, a headset mode and a hand-free mode. A hands-free telephone set or telephone terminal includes a sound pick-up device with one or more microphones, a sound output device with one or more loudspeakers and transmit and receive signal processing circuits. A telephone set has a memory for storing the telephone number of the caller. During the absence of the user of the telephone set, when the telephone set is called, the memory stores the telephone number of the caller. After the end of the absence, the user can call back the caller by referring to the caller telephone number stored in the memory. Telephone sets come in many different styles and usually include a number of features which are tailored to the user's needs. With respect to the outer structure of telephones, they can usually be divided into two categories, table top models and wall mount-type models.