Sounds of history 'at great risk', say US researchers
Sound recordings forming part of our cultural history are in grave danger of disappearing, says a comprehensive report from the US Library of Congress.
The report warned of both the physical and legal barriers to the preservation of sound recordings old and new.
Lack of access to older recordings mean that only 14% of pre-1965 US recordings are available to the public.
The report also warns that no comprehensive programme exists to preserve "born digital" recordings.
It reiterates the long-established fact that many digital media such as recordable CDs have a lifetime significantly shorter than earlier technologies.
But it also raises the point that some media are not being captured at all.
"We're finding that some of the older media like shellac discs and vinyl discs are quite stable, and if stored in reasonably good conditions will last another hundred or two hundred years," said Sam Brylawski, co-author of the report, titled "The State of Recorded Sound Preservation in the United States: A National Legacy at Risk in the Digital Age".
"'Born digital' audio - things that are disseminated on the internet through websites or podcasts - are at great risk. We need to be able to have a process to harvest them and sustain the files," he told BBC News.
Conversely, the 181-page report looks into the "unnecessary redundancy" of preservation efforts in multiple places; the report calls for means to "enable institutions to share data about recordings held in common and to locate source recordings that are in the best condition to serve as candidates for preservation".
The report goes on to examine the degree to which copyright law plays a role in the ability to duplicate - and thereby to more securely preserve - recordings.
"US copyright law impedes preservation and access in many ways and that needs to be looked at," Mr Brylawski explained.
"In most European countries, the copyright for sound recordings is 50 years; in the US, there are no sound recordings in the public domain and there won't be any until 2067.
"An 1895 wax cylinder is protected by state law and common law copyright until then and that's impeding access and preservation."
A spokesman for the British Library told BBC News that "the decay of the storage format only tells half the story".
"As the Library looks to continue in its role as custodian of the nation's cultural and intellectual memory in the digital age, efforts are being made to not just ingest terabytes of data but also ensure we preserve the growing volume of important digital material being created in the UK.
"This is obviously a major challenge for the British Library, the Library of Congress, and any other institution or organisation that needs to preserve digital material for future access, whether it be a sound recording, a photograph or somebody's health records."