Archival Formats for Audio Digitization
Archival master copies should always be stored in uncompressed formats, either WAV or AIFF. WAV was developed for Windows, AIFF for Macintosh, but each can be used on either operating system. These files are quite large (approximately 10 times larger than standard compressed formats), and the difference between compressed and uncompressed audio is generally undetectable by the human auditory system. However, the retention of all of the original data is important for long-term preservation, especially for the irreplaceable recordings of languages that are extinct or moribund. Phonetic analysis is especially dependent on an accurate view of the data. Audio stored in uncompressed format can always be compressed later for presentation online, distribution on discs, etc. Furthermore, the uncompressed file can be edited and re-saved without loss of data, unlike compressed formats such as MP3, which re-compress the file, with concurrent loss of sound quality, each time the "Save" icon is clicked.
In general, the master copy should not be cleaned up or enhanced in any way, since this entails a loss of some portion of the original data. Presentation copies may be processed whenever appropriate to make the sound more accessible, but the archival master should be a faithful representation of the original recording. Given the continuing and rapid progression of technology, current applications for sound enhancement are likely to be replaced in future by improved versions. Keeping a pure copy of the audio file will make it possible to apply better enhancement applications as they become available.
See also Sound Directions: Best Practices for Audio Preservation.
How to Record Audio
Dena'ina Case Study