Audio

Main Page > Documentation > Media type preservation plans > Audio

Preservation Format

LPCM/WAVE

Access Format

MP3

Normalization tool

FFmpeg

Comments

• Audio files are normalized to WAVE LPCM with a bit depth of 16 bits per sample and a sampling frequency of 48000 HZ.
• Library of Congress considers WAVE LPCM as the "preferred format for sound recordings." Library of Congress Sustainability of Digital Formats: WAVE Audio File Format with LPCM audio
• Florida Digital Archive normalizes audio streams contained in WAVE files to uncompressed PCM(LPCM) with a bit depth of 16 bits per sample. See Preservation action plans: WAVE.
• According to Guidelines for the Creation of Digital Collections: Digitization Best Practices for Audio, Consortium of Academic and Research Libraries in Illinois, 2009, WAVE LPCM with with a bit-depth of 16 bits and a sampling freqency of 44000 HZ is the minimum standard for a preservation format. Higher bit depth and sampling frequencies may be desirable: "Several specific reasons for richer files include: the accurate capture of noise like clicks, pop, and other inaudible information that resides in frequencies higher than 44.1 kHz; desire to communicate inaudible harmonic information that impact perception of sound; ability to record and provide content that, although not necessarily heard, helps listeners understand and hear better space, depth, and instrument location in stereo and surround sound recordings; and to accommodate future user applications."