资料来源 : 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)