The mechanical devices used for oral communication are:
(a) Telephone
(b) Loudspeaker System
(c) Recorded message
ADVERTISEMENTS:
(d) Dictating machine,
(a) Telephone – Telephone is a mechanical device meant to reproduce sound at a distance through the help of cables or wires. It is a convenient and quickest method of communication.
(b) Loudspeaker System — It is a traditional mechanical device and is a type of public address system. These are used in railway stations, bus stands and airports to call persons or give instructions.
(c) Radiophone — It is a device where instruments are not connected with wire but facilitate oral communication. This is otherwise called as wireless system.
ADVERTISEMENTS:
The other facilities of oral communication are through recorded message in cassettes and magnetized discs or tapes and through a dictating machine.