資料來源 : Free On-Line Dictionary of Computing
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 {bit}s
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
(ftp://ftp.cwi.nl/pub/audio/AudioFormats.part1)}, {Part 2
(ftp://ftp.cwi.nl/pub/audio/AudioFormats.part2)}.
(1999-07-30)