Pages

Monday, November 17, 2014

Changing Audio File Formats for Genealogy



One of the challenges of gathering genealogical data from family members is the existence of a variety of audio files. How many genealogists have a cache of old cassette recordings or even recordings on audio tape? As technologies change, these old recordings are in danger of being lost due to the unavailability of adequate ways to transfer the files to newer formats and devices. Fortunately with audio files, it is possible to simply play the recording and re-record the output into a digital format. Even more recent formats, such as CDs, are now swiftly disappearing from the marketplace. It is a good idea to focus on these recordings now, while some of the older recording devices are still around and in good enough shape to play the recordings.

Audio recording began in 1860, seventeen years before the Edison recording shown in the above video. Quoting from the website, FirstSounds.org press release on the subject:
A group of researchers has succeeded in playing a sound recording of a human voice made in 1860 – 17 years before Thomas Edison invented the phonograph. Roughly ten seconds in length, the recording is of a person singing “Au clair de la lune, Pierrot répondit” – a snippet from a French folksong. It was made on April 9, 1860 by Parisian inventor Édouard-Léon Scott de Martinville on his “phonautograph” – a device that scratched sound waves onto a sheet of paper blackened by the smoke of an oil lamp.
The first analog devices, such as those invented by Thomas Alva Edison, all involved a physical reproduction of the sound waves in some media such as wax or rubber. See Recording History, the history of recording technology. If you have any of the old wax cylinders or very old phonograph records, they are valuable collectors items and should be carefully preserved. See the Library of Congress' "Save Our Sounds: America's Recorded Sound Heritage Project."

There are a variety of ways, beyond simply playing the recording and re-recording it, to transfer the sounds to a digital device. Unfortunately, most of these conservation techniques are very complicated and require highly specialized equipment. Here is a description of the process of digitally recording was cylinders from the Department of Special Collections of the Donald C. Davidson Library at the University of California, Santa Barbara:
Cylinders were transferred using a French-made Archeophone, using custom Shure styli from Expert Stylus in England. The audio was converted from analog to digital using a CEDAR ADA and captured at 44.1KHz with a bit depth of 24 bits in Steinberg Wavelab software running on a PC. Files were edited and normalized and then processed with CEDAR's Series X and Series X+ Declicker, Decrackler, Dehisser, and Debuzzer units. After "cleaning," a third file, dithered down to 16 bits, was created. Surrogate files for online distribution were created with Sound Forge 6.0's batch converter (mp3 files) and Cleaner XL (mov files). After 2009, cylinder transfers have been captured simultaneously as raw and processed wav files by splitting the digital signal, routing one channel through the CEDAR components and recombining them and capturing simultaneously on the DAW as two mono wav files.
Later recordings are easier to capture. There are a number of USB phonographs for sale. Simply do a search on Google for "usb phonograph." There are also a number of commercial services that transfer all types of wire recordings to digital format. I hesitate to list any of these because I do not know their quality of recordings. Try searching for "audio recording transfer digital" for those presently available.

Once you have a digital audio file, your conservation efforts are only beginning. Wikipedia lists 30 different digital audio file formats. I use Audacity from Audacity.SourceForge.net but there are several other programs available. Once again an online search will give you several options.

For my present audio recordings in my oral history project, I am using a Sony digital recorder with a microphone and it works wonderfully.

No comments:

Post a Comment