The Tin Can Telephone

By Bobby Neal Winters

When I was a kid, there was no such thing as trash service in rural areas.  You burned your trash to minimize its total volume.  Then, when your burn barrel was full of things that would no longer burn, you hauled it off an dumped it in a isolated area where no one was looking.  I’m not proud of it, but that’s the way it was.

Sometimes we dug tin cans out of the trash and made phones out of them.  The idea is simple and I am sure many of you have done it--or something similar--yourselves.  You take two cans, put holes in the center of the bottom, and attach the cans with a light string.  You then holed the cans so the string is taut and talk into one can while someone listens in the other.

The model for communication theory is only a little more sophisticated. You have the equivalent of the two cans: call one the transmitter and the other the receiver.  And you have the string: call in the channel.

Instead of talking on one end and hearing on the other, you are sending symbols on one end and receiving them on the other.  When we say symbol, you can think what you want; the model is abstract enough to admit just about anything.  In practice, the folks who do this sort of thing will think of a symbol as being a string of ones and zeros.

The channel--the string, as it were--brings in an little more complication because it is a device through which we can add noise to the signal.  Those of us who have used the tin can telephone know that sometime the wind would whistle through the string.  This model will allow for that, but it will also allow for electromagnetic disturbances disrupting those ones and zeros being transmitted.

As an exercise, think about the following situation. Agents have captured an enemy operative.  She is a beautiful blond bombshell, a perfect exemplar of the “Bond Girl.”  You send a message, “Kill the prisoner.”  As you do, lightning strikes and your agents receive, “Ki** the prisoner.”  

There is ambiguity in the message.

While it can be reconstructed correctly, it can also be reconstructed as, “Kiss the prisoner.”  Depending upon the proclivities of your agents, they might find this message more attractive.

One value in creating a system to communicate effectively is to minimize the chance of this sort of ambiguity.  One way around it is to create a code wherein only certain things can be said.  This book, possibly, wouldn’t include the possibility of kissing an agent.  In practice, the symbols of ones and zeros are constructed so that only a few strings of ones and zeros are acceptable and corrupted ones are no longer in the alphabet, as it were.

The military does this with they so-called phonetic alphabet.  Interpreting strings of letters over a telephone line can be difficult.  The letters ess and eff  can sound the same, for example.  Instead of saying “Ess eff,” which could be heard either as “ess ess” or “eff eff,”  using the military phonetic alphabet you would say “Sierra Foxtrot.”  A set of symbols has been created so that, even when transmitted over a noisy channel, there is a reasonable chance of recovering the original symbols.  

So you could say “Kilo India Lima Lima” the prisoner and that wouldn’t be heard as “Kilo India Sierra Sierra” the prisoner.

What we’ve done here is to start talking about using a code.  The word code is often used to mean hiding the meaning of a message as when we say that people are talking in code to one another.  This is what mathematicians refer to as encryption, which is a different sort of thing. Encryption is about hiding meaning, but codes are about trying to transmit messages accurately.  I won’t chide you about blurring the distinction in casual speech, but in this context I will keep the distinction.

One practical issue that does occur in communication is whether the transmitter and receiver have the same code book.

I was watching a television show the other night where a young woman invited her date for the evening in for “a cup of coffee.”  His code book interpreted that phrase to mean an invitation for a hot, caffeine containing drink.  In her code book, it was intended to convey the possibility of insuring wakefulness by other means.

This is by no means an artificial example, nor is it unique. When adults are talking to children, the children have a different code book, as there vocabulary is smaller.  Communication is possible between parent and child though there is sometimes frustration in both direction.  There is also much comedy, as in the preceding paragraph, based on the characters having different code books.

It seems to me that an important element in basic communication is for the transmitter to know as well as possible what code book the receiver has and to craft the message accordingly.

The folks in marketing are masters at this.  They will tailor their messages to a particular demographic, folks with a particular code book and get their message through to that market.

In talking so much about the transmitter and receiver, let’s not forget about the channel.  There is only a certain amount of information that can be sent across a channel.  What is not sent can be as important as what is sent.

There have been time when I’ve met people in church.  They’ve got nice clothing on.  They are driving a late model car.  The overall impression, their image, is one of prosperity.  The truth is that they live in a modest home and that the car isn’t paid for and the clothing are saved for special occasions.  They can make themselves look rich by hiding their bank accounts and their homes.  It’s not only what is seen; it’s what’s not seen.

Celebrities make use of this as well.  They have their image, their public persona, but they have their private selves as well. For them, the image is a commodity that they sell just like a farmer sells produce.  They must master what is seen and what is unseen.

It is a mistake, though, to believe that only celebrities have images.  Each of us has an image as well.  We use different language for it; often we call it a reputation.  It doesn’t take long to get one, and once you’ve got a bad one it can take a while to improve it.

We build our images, our reputations, by the signals we send.  Some are masters of image creation.  It is relatively easy to convey an image of being prosperous; you just have to be sure to spend your money where people can see it.  It is relatively easy to appear to be intelligent; much of time it consists of keeping your mouth shut.

Beyond that you have to know your market and what code book they have.  It also helps to be rich, smart, or whatever you are trying to portray yourself to be, but because of the narrowness of communication channels, it’s not always necessary.