6.4.2 Future Digital Pathways

6.4.2.1  When a file format becomes obsolete and is at risk of becoming inaccessible due to the unavailability of appropriate software to access the content, there are basically two approaches that can be made; migration, or emulation. In migration the file is modified, or migrated to a new format, so that the content can be recognised and accessed using the available software of the time. In emulation, the access or operating software is modified or designed so that it will open and play the obsolete audio file format on a new system which would not otherwise be able to open the content.

6.4.2.2  Our current understanding leads us to believe that for simple discrete files, such as uncompressed audio files, the most likely approach will be migration but this is not certain and all digital storage approaches and systems should be flexible enough to be responsive to the changing environment. Adequate preservation metadata as described in the PREMIS recommendations or the explicit file typing (including versioning) in BWF/AES31-2-2006 fields will support either approach, as will the standards being developed in AES-X098B which will be released by the Audio Engineering Society as AES57 “AES standard for audio metadata – audio object structures for preservation and restoration”. Harvard University is developing a toolkit which supports the population of the necessary fields which will be released in open source.

6.4.2.3  This aspect of digital preservation is the strongest argument for an absolute adherence to the standard format described. The large investment the audio and IT industries have made in the standard audio format (.wav) means that the requirement for professional software tools which will enable the continued access to content will help to ensure that the sound archive can manage access to their collections. Likewise, the large investment in a single format will also help support the continuance of that format for the longest period, as the industry will not change an entrenched format without significant benefits.