digital audio

digital audio

(1) Sound waves that have been sampled, digitized and stored in the computer. Common formats are music CDs, MP3, WAV and AIFF, and software-based players play the largest variety of audio formats (see media player).

Musical Instrument Digital Interface (MIDI)
Although digital, the MIDI format differs from all other digital audio formats. MIDI files contain a coded version of the musical score, not the actual sound (see MIDI). Contrast with analog audio. See CD-DA, MP3, codec examples and S/PDIF.

(2) Broadcast radio in digital format. See HD Radio, DAB and satellite radio.

(3) See digital CD audio.

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(multimedia, file format)

digital audio - A sequence of discrete samples taken from a continuous sound (audio) waveform. Tens of thousands of samples are taken each second. Each sample represents the intensity of the sound pressure wave at that instant. Apart from the sampling frequency, the other parameter is the digital encoding of each sample including the number of bits used. The encoding may be linear, logarithmic or mu-law. Digital audio is typically created by taking 16-bit samples over a spectrum of 44.1 thousand cycles per second (kHz), this means that CD quality sound requires 1.4 million bits of data per second. Digital telephone systems use lower sample rates. Filename extension: .au (Unix), .snd (MS-DOS, MS Windows). See also Audio IFF, MP3, wav. Usenet newsgroups: alt.binaries.sounds.*. A FAQ on audio file formats is available. Part 1, Part 2.