Hello Future, Can You Hear Me?

Email a Friend
Signal, go forth Into the great unknown

Last week we presented an allegory for retrieving audio, where we compared it to listening to a distant radio station. Of course, that is only half of what audio archivists do: the other half is to try to extend the reach of that signal into the future.

Let us then modify our original allegory. Imagine that, instead of you trying to catch a particular broadcast, you find a note next to your clock radio:


There are two ways to fulfill this request: you could either try to ensure that the original signal reaches Claude's receiver, or you could capture that signal, boost it, and re-transmit it with your own antenna. Once again the two key considerations in your decision will be the quality of the signal at your location and your available resources. Let's look at each in turn, since this time we are looking at them from the other side.

1. Quality of present signal

If you think the signal will reach Claude's receiver, you may choose to do no more than tell Claude how to retrieve it from his location (telling him, for example, to what frequency he needs to tune his dial). You could also take extra steps to safeguard the signal's path, for example by removing obstacles between the original transmitter and Claude's location, or by extending its range through other, more exotic means.

Audio archivists perform an equivalent task by trying to extend the life of the physical media in their collections. Although all things must end, proper care can extend the life of most carriers by a significant amount —and we are constantly learning how to do it better.

2. Resources

If you have enough resources or are not sure the signal will make it to Claude's receiver, you may want to boost the signal you receive and send it his way. This is a two-step process: you first capture the signal and then you re-transmit it. Capturing the signal is tricky and, if not done carefully, can significantly degrade what you send to Claude. But once you capture it, other broadcasting avenues open up: you can boost the signal, perhaps use a different frequency, or send it via cable; even convert it to digital information. Rebroadcasting the signal will allow it to reach further, but at the price of using more resources; and unfortunately, more robust processes (such as digital) tend to be more expensive. (It is also worth noting that, since Claude is further from the original broadcaster, he will likely never get to hear the signal as well as you do)

Audio archivists, concerned with the longevity of their media, engage in an equivalent process called reformatting, where they transfer a signal from one carrier to another to extend its practical life. Until fairly recently this was an analog process, where, say, audio from a fragile disc was transferred to a longer-lasting tape. Nowadays it is a digital process, since digital signals are potentially more reliable and easier to access —although the safekeeping of those signals seems to be more expensive, at least for now.

Location, location, receiver

You have probably noticed that your decision of whether to extend or retransmit the signal would be much easier if you knew where Claude is, or at least how far from you. Unfortunately, to keep our allegory honest, you would not know. This means that, given limited resources, you will have to guess by how much you need to boost the signal to ensure it reaches Claude.

It would also be very helpful to know what kind of receiver Claude has; but, again, you would not know. If you knew that he has, or could easily find (or build) the same kind of receiver you have, you may choose to just let the signal through. Otherwise you will have to guess and hope that the kind of signal you rebroadcast can be decoded on his side. The further Claude is, the less certain you will be —are, say, European receivers the same as North American ones?²

Content is king

Since it would be impractical to extend and rebroadcast on many channels all of the original signals you receive, you will have to take stock of your resources and choose which signals are worth what expense. This (difficult) decision will greatly depend on content quality, which is of course very hard to quantify: what is interesting to you or your immediate neighbors may not be interesting to Claude or people elsewhere.

Managers of audio collections go through the same processes as described above, and often opt for a dual approach: they try to extend the life of their physical media through environmental controls, and they also reformat their collections. This approach is taxing on their resources, ultimately just a guess, and impossible to evaluate beyond a few years. But try they must.

There is a concept in aeronautics called gravity assist, where spaceships use the orbital pull of planets to increase their reach. Audio archivists play a similar role to those planets, sling-shooting signals into outer space, hoping someone will listen.


¹A name combining Claude Shannon (1916-2001) and the name Zenon, "receiver of life."

²In fact, they are not.