An audio optical disc is an optical disc that stores sound information such as music or speech. It may specifically refer to:
Audio CDs Compact disc (CD), an optical disc used to store digital data (700 MB storage) Compact Disc Digital Audio (CD-DA), a CD that contains PCM encoded digital audio in the original "Red Book" CD-DA format 5.1 Music Disc, an extension to the Red Book standard that uses DTS Coherent Acoustics 5.1 surround sound Compressed audio optical disc, an optical disc storing MP3s and other compressed audio files as data, rather than in the Red Book format
Audio DVDs DVD, 4 GB single layer, 8 GB double layer storage DVD-Audio, a DVD that plays audio Super Audio CD (SACD), a format which competes with DVD-Audio
Audio Blu-rays Blu-ray, 25 GB single layer, 50 GB double layer BD-Audio, a Blu-ray disc that is capable of audio-only playback
See also Compatible Discrete 4 (CD-4), a variety of quadrophonic audio for vinyl records