Definition: audio codec

(1) (audio enCOder/DECoder) Software that compresses and decompresses a digital audio signal. MP3, Windows Media Audio (WMA), Dolby Digital and DTS are examples of popular codecs that compress and decompress digital audio. The audio codec may also be a hardware circuit. See codec examples, codec, Windows Media formats, QuickTime, audio compression, perceptual audio coding and G. standards.

(2) (audio enCOder/DECoder) A hardware circuit that converts sound waves into PCM digital code and vice versa. The term may refer to only the A/D and D/A conversion, or it may include the compression technique for further reducing the signal (definition #1 above). If the codec is specialized for human voice, it is known as a "speech codec," "voice codec" or "vocoder" (see speech codec). See sampling and codec.