use Perl

• .swf Decompiler (Score:2)

  by Mr. Muskrat (4572)

  Find yourself a .swf decompiler. The .swf file will generally contain a sound file of a well known type (.wav, .mp3, etc).
• SWF to MP3 (Score:1)

  by ChrisDolan (2855)

  Try this: swf2flv [cpan.org] and flv2mp3 [cpan.org].
  
  Internally, most SWF audio is just chunks of MP3. If it fails, feel free to submit a report to RT and I'll look at it.
  • Re: (Score:1)

    by ChrisDolan (2855)

    OK, I actually tried it and, in this case, the audio is not embedded in the primary SWF, but is loaded from an external URL. See this screen capture from Safari's activity monitor showing all of the URLs loaded by that SWF, including many MP3 files.
    
    http://chrisdolan.net/misc/Spike-mulligan-activity.png [chrisdolan.net]