Audacity AU
From Just Solve the File Format Problem
Audacity[1] is an FOSS audio editor. Audacity uses the AUP to store projects and up until version 2.4.2 used the AU audio format to store the project audio.[2] Not to be confused with the Sun/NeXT AU files with the same extension.
File Information
AU block files are lossless/uncompressed PCM data. Metadata on their properties is in the AUP file. AU block files must be kept in the structure created by Audacity 2.x[3].
