1-2. WORDS TRANSFER INFORMATION
A perfect communication system conveys information without modifying the original order and form of that
information. However, a perfect communication system cannot compensate for the inability of the message
originator to choose the correct words needed to accurately convey the intended thought. Neither can a correctly
functioning communication system be held accountable for the failure of the listener or message reader to
understand the message content. Technological advances have achieved great speeds of message transmission
and reception. But our inability to express ourselves completely sometimes results in unexpected and undesirable
communication delays. Often people have difficulty in communicating thoughts because the words they choose
may not accurately convey the intended thoughts. The point being emphasized here is that no communication is
complete until the receiving party acknowledges understanding of the message contents. Acknowledgment of
receipt of the message does not in itself indicate nor guarantee that the message has been understood.
1-3. PICTURES TRANSFER INFORMATION
We all know from experience that a picture has the power to convey more information in less time and with
greater accuracy than any other means of communication. This capability stems from the fact that what the eye
sees, the mind interprets. The need for words to form the mental picture is thereby removed. If you want to
experiment with this, try to describe in detail an electronic circuit or a weather map. Try as you might to be
accurate, your listener will most likely form incomplete or inaccurate mental pictures from your word definitions.
Transmission of pictures, maps, and diagrams by facsimile or television greatly enlarges the capability of military
communication systems to transfer information. Pictorial transmission also has the ability to provide a "hard" or
printed page copy. However, teletypewriter is a more practical means of providing a hard copy.
1-4. COMPONENTS OF SPEECH
Each of us has a characteristic speech pattern, and no two individuals speak exactly the same. The reasons for
our speech being characteristically different are many and varied. A discussion of a few of these reasons will
establish the need of a voice communication circuit to faithfully reproduce voice sounds. The principal
determinants of voice characteristics are amplitude and frequency.
a. Amplitude. Amplitude is the loudness with which we speak. Some of us speak more loudly than others.
Those who speak too loudly sometimes overload the amplifiers in communication systems and thereby destroy
some of the voice quality by their own actions. Those who speak too softly will have difficulty being heard at the
receiving end of the circuit.
b. Frequency. Frequency components in a voice signal are very complex. The combination of frequencies
(pitch) in each voice gives it a characteristic sound. If an appreciable number of the frequencies that make up the
voice sound are removed during signal transmission, we may have difficulty understanding the spoken words.