Audio File Format Guidelines

The Bentley Historical Library prefers to receive uncompressed WAVE audio files (commonly identified by a .WAV file extension). Uncompressed WAVE is regarded as a sustainable preservation format due to the format's quality, widespread use, and capacity to store information (i.e. 'metadata') about the audio content itself.

WAVE File Specifications

The following information identifies various levels of quality for WAVE audio files that may be submitted to the Bentley Historical Library. The ability of donors or content creators to conform to these guidelines may depend upon hardware/software features and/or individual technical expertise.

  1. Basic:
    • uncompressed .WAV
    • Plain text file or spreadsheet with metadata (information about the recording):
      • performer(s) or content creator
      • title (if applicable)
      • description of subject matter
      • date of event/performance
  2. Intermediate (CD quality):
    • uncompressed .WAV
    • 16 bit PCM (Pulse Code Modulated) encoding
    • Recorded at 44.1 kHz
    • Plain text file or spreadsheet with metadata (information about the recording):
      • performer(s) or content creator
      • title (if applicable)
      • description of subject matter
      • date of event/performance
  3. Advanced (archival quality):
    • uncompressed .WAV
    • 24 bit PCM (Pulse Code Modulated) encoding
    • Recorded at 96 kHz
    • Plain text file or spreadsheet with metadata (information about the recording):
      • performer(s) or content creator
      • title (if applicable)
      • description of subject matter
      • date of event/performance
  4. Advanced++: Broadcast Wave Format (BWF)
    • CD or archival quality .WAV file
    • Metadata written to the Broadcast Audio Extension (or "BEXT") chunk of the .WAV file header (instead of or in addition to the text file/spreadsheet).

Other Audio File Formats

If donors or creators are unable to produce uncompressed WAVE files, the Bentley Library has used guidelines put forth by the Library of Congress, to identify several other audio formats that are 'sustainable' due to their wide use and non-proprietary status. For more information, consult the Division of Digital Curation's table of sustainable formats. The audio content in these files should be uncompressed (or created with 'lossless' compression).

If the Bentley Historical Library receives audio in 'at-risk' (i.e. proprietary or technically obsolete) file formats, archivists may be able to migrate the content to the .WAV format. For more information, consult the library's current format migration strategies.

Audio in file formats other than those listed in the sustainable formats table and format migration strategies, may be deemed inappropriate for the Bentley Historical Library's digital collections. If such file formats are accepted (as part of a larger transfer, for example), they will be preserved in their native state but no guarantee can be made that the audio content will be accessible or playable in the future.