Eren Delaney is the Digital Preservation Specialist and Rachel MacGregor is the Digital Preservation Office at the Modern Records Centre, University of Warwick.
As an archives service, the Modern Records Centre’s main aim is to preserve and provide access to the historical material that we look after, seeking to maintain its existence in its current form for as long as possible. Our mission statement could well be "Save Our Stories" and we work hard across a wide range of collections to preserve endangered heritage. We are primarily responsible for paper, photographs and increasingly digital records and we are not an archive specialising in audio visual formats, however inevitably a wide range of formats and carriers turn up in the records we receive. Our paper-based records are stored in temperature-controlled, humidity-controlled, and pest-controlled environments; this is the best way to ensure that the paper continues to exist, undamaged and unchanged, for hundreds of years.
Just a few of the obsolete and obsolescent format types at the MRC.
As an archives service, the Modern Records Centre’s main aim is to preserve and provide access to the historical material that we look after, seeking to maintain its existence in its current form for as long as possible. Our mission statement could well be "Save Our Stories" and we work hard across a wide range of collections to preserve endangered heritage. We are primarily responsible for paper, photographs and increasingly digital records and we are not an archive specialising in audio visual formats, however inevitably a wide range of formats and carriers turn up in the records we receive. Our paper-based records are stored in temperature-controlled, humidity-controlled, and pest-controlled environments; this is the best way to ensure that the paper continues to exist, undamaged and unchanged, for hundreds of years.
For other types of records, the formats themselves are the issue, presenting a risk to the longevity of their content. This is particularly true of ‘legacy media’; outdated or obsolete audiovisual formats or data carriers. This includes a wide range of formats including reel-to-reel tape, floppy disks, audio cassettes, videotapes, CDs and DVDs, and USB sticks - and yes, unfortunately even the ones you grew up using are now formally ‘obsolete’.
The issues these formats present fall into two broad categories. Firstly, the formats themselves are at risk of physically deteriorating, to the extent that their content is corrupted or wholly destroyed. Repeated playback and poor handling can be a risk to many formats - for example, CDs and DVDs can be scratched easily. For other formats, such as videotapes, repeated playback can wear the tape itself. For both types of legacy media, appropriate archival conditions can extend the life of the media - but not forever.
Another risk to the preservation of legacy media is that ways to access them are increasingly rare and difficult to find. Unlike paper–based records, legacy formats and carrier media must be accessed through an interpretive medium to either read or play their content, whether that be software or hardware. For formats that are both obsolete and rare, getting hold of equipment can be difficult and expensive. This threatens to be the case for more and more formats in the future unless reading equipment is intentionally sought and also maintained by archives and similar institutions. For the non specialist archive we can never hope to manage and maintain the range of equipment required.
At the MRC, one collection that contains a significant proportion of audiovisual material stored on legacy media is our ‘Make Poverty History’ campaign collection. This collection tells the story of the organisation and orchestration of a 2005 campaign to influence the policies of several governments to prioritise foreign aid and reducing global poverty. The campaign was held in 2005, a year when the UK was hosting the G8 Summit, an annual meeting of the international coalition then made up of Canada, France, Germany, Italy, Japan, Russia, UK and USA, and was also the 20th anniversary year of Live Aid, an internationally famous benefit concert that aspects of the campaign were styled after. Many celebrities and notable figures were involved in the campaign, from Bono to Nelson Mandela.
The characteristic white wristband produced for MakePoverty History (representing yet another preservation challenges!)
The audiovisual component of the collection covers broadcast radio and television content that made up part of the campaign, as well as video footage of protests and demonstrations. Some of the content is in a format we have the capacity to digitise and make available at the MRC, such as the more common VHS and audio cassette tape formats. For others, however, such as the Betacam formats contained in the collection, we don’t hold the hardware required to play or digitise the content, and so the content is currently inaccessible to researchers. Formats such as these which truly represent our heritage in danger.
A box of various audio visual media carriers from MakePoverty History Archive.
At the Modern Records Centre we digitise tapes using a TEAC LP-R550USB, a multi-format audio digitisation system that it compatible with CD, audio cassette and vinyl formats, seen here in situ in our digitisation suite.
Our audio digitisation equipment.
This system converts the analogue audio signal into a digital signal and transmits that to our workstation through a USB connection. We use the audio editing software Audacity to save the transmitted digital signal as a file. As part of this process, we first listen to a section of playback of the tape and manually adjust the audio input level for each tape as it is digitised. The volume of the recorded audio is represented within Audacity as a waveform as it is being digitised:
Visualisation of the waveform output from Audacity during digitisation process.
Should the waveform be too small, the recorded audio may be too quiet and hard to listen to upon playback. Should the wave 'peak' or exceed the maximum amplitude limits of the system, there will be distortion or 'clipping' on the digitised audio file, which presents as crackling or harsh-sounding audio upon playback. Manual adjustment is therefore a balancing act of trying to achieve the best quality audio without causing excessive clipping. Due to the range of recording conditions and quality across tapes, the required levels can be different for different tapes or collections. The resulting audio files are saved as preservation-quality Broadcast Wave (BWAV) files, and also as MP3 files for access copies. We can also encounter further issues with the tape stretching or snapping , so the process can be quite labour intensive.
Once the content of the carrier is captured then comes the long term preservation part. We can be sure that at least we will be able to give access to the collections without worrying about maintaining old equipment but this is the start of the digital preservation process. The output files are saved to our secure server space and added to our Digital Asset Register, which records all our digital content, whether born digital or digitised as a result of preservation and access programmes. The Asset Register helps us prioritise both preservation workflows and access so we can ensure we have captured appropriate metadata about file formats as well as details about any access restrictions which means we can plan where and how the material will be made available. At this point the origin copy of the file will be ingested into the preservation system, so that it's secure and available if further access copies are required. The preservation system also ensures that this copy is auditable and tracked to make sure it too does not become as obsolete as its analogue parent. As for the original cassette, we keep these, partly to capture any additional metadata written on the cover (although this is also photographed and stored alongside the digital copy) and partly to ensure that if a later issue emerges with the digital copy we still have the original to fall back on. Access versions are made available via a variety of channels including our catalogue and website (for example hear a selection of audio made available here. However there is still a huge amount of work to be done and time is running out to Save Our Stories.