Video narration
How does your voice reach your friend's phone when you make a mobile call? Not directly-it is converted, prepared, carried, recovered, and changed back into sound. It begins with the information source: your message. The input transducer, the microphone, changes sound into an electrical signal. The transmitter prepares that signal and sends it onward. The channel is the path, wireless here, though it can also be cable or optical fibre. During travel, unwanted interference adds noise. At the other phone, the receiver accepts the disturbed signal and recovers the original voice. Then the output transducer, the speaker, changes that electrical signal back into sound. Your friend is the destination. The path is: information source, input transducer, transmitter, channel with noise, receiver, output transducer, and destination. Your voice becomes electrical, travels through a channel, and is recovered as sound on your friend's phone.