What Speed Is This? The Challenge of Obsolete Audio Recordings
By Sally Jacobs, Audio Archivist
Here at the Wisconsin Historical Society Library-Archives, we are able to play back (can we say "listen to" or "play" instead of play back?) and digitize a wide variety of recorded sound formats. Some are truly obsolete. These include (are these the obsolete ones?) DJ Carts, 16-inch radio transcription discs and wire recordings -- to name just a few.(need to give readers context, how were these used in the past?).
On the other hand, there are some formats we cannot currently play back. Grooved dictabelts (what is this?) will have to wait until we have an Archeophone machine, (what is this?) and with a list price of over $10,000 it’s going to be a long wait.
Our extensive collection (of what? audio recordings?) includes formats we can easily digitize, plus a small number of formats we know we cannot. But this article isn’t about either of those. It’s about a format that falls somewhere in between, and what we did to fix it.
Dictation? What’s Dictation?
Before personal computers, dictation was a common way to compose a business letter or write a draft. The author would “dictate" information by speaking the words out loud. Another person, usually a stenographer or secretary, would “take dictation" by writing down all the words as they were spoken. Skilled stenographers captured the spoken words with shorthand, a simplified form of writing that used symbols and abbreviations so the notetaker could keep up with the speaker.
Dictation machines allowed more flexibility (for whom? How so?). Various brands and styles competed with each other between the 1870s and the 1980s. A dizzying array of formats (of what? Recording hardware within dictation machines?) existed, including discs, cylinders, belts, wires, and tape cartridges.
Preparing William Proxmire’s Red Voicewriter Discs for listening on the Web.
The Society holds the papers of William Proxmire, a U.S. Senator from Wisconsin known for curbing governmental waste and mismanagement. He served from 1957-1989 and during that time gave 3,211 speeches arguing that the United States should sign the United Nations Convention on the Prevention and Punishment of the Crime of Genocide. Those speecshes are stored on Red Voicewriter Discs he used for dictation.
While Proxmire Digital Collection, our Audio Lab was asked to digitize a selection of his recordings for presentation on the Web. Proxmire used Voicewriter discs (need a description of what this is, how it works, etc.)
The cover of one of Proxmire’s Voicewriter discs.
You can see the handwritten notes about the content
The Red Discs.
As you can see, each has an A side and a B side.
Proprietary, Non-Standard Playback Speed
His Voicewriter discs fit just fine on our turntable, but when we played the disc we figured out pretty quickly that the RPM (revolutions per minute) wasn’t any of the standard speeds we could play. In addition to 33 1/3RPM and 45 RPM, our turntable can also handle 16 PRM and 78 RPM. Usually, this is more than adequate.
After suggesting that he capture the discs digitally by playing at the closest speed, I let our Audio Specialist, Frank, take over. My hope was that Frank could fix the speed digitally with our ProTools software. Without this fix, we had a William Proxmire who sounded like Donald Duck.
First step? Find a sample of Proxmire speaking at a normal speed. Second step? Frank used his ear to shift the speed and pitch of the digitized Voicewriter to match it.
Later, he learned from his colleague at the British Archives that Voicewriter RPM varied between 22 and 24. The variation was due to battery power. Here’s Frank’s explanation of what they do in London:
"My pal at the British Archives indicated they have a special modified turntable for just this purpose, and he uses a very clever technique to determine the correct speed by running any hum off the recording (a frequency of 50 or 60hz depending on country origin) into an outboard (not software) buzz and hum remover and adjusting turntable (or tape deck) speed to where that hum is identified on the device. When it is- he found the correct speed! I should mention that they prefer to capture all content at original speed and do no speed/time adjusting in software as to retain an 'unprocessed master' of the original content."
Listen to the Before & After
Click here to listen to the raw capture and compare it to the digitally “fixed” version. [These files are stored at R:\Audio\Proxmire Time Shift Fix]