title: pydub export not working
body: <p>I found this pydub example here on github :</p>
  
  <pre><code>    from pydub import AudioSegment
      from pydub.silence import split_on_silence
  
      sound_file = AudioSegment.from_wav("testsample.wav")
      audio_chunks = split_on_silence(sound_file,
         # must be silent for at least half a second
           min_silence_len=500,
  
         # consider it silent if quieter than -16 dBFS
           silence_thresh=-16
      )
  
      for i, chunk in enumerate(audio_chunks):
  
          out_file = ".//splitAudio//chunk{0}.wav".format(i)
          print "exporting", out_file
          chunk.export(out_file, format="wav")
  </code></pre>
  
  <p>It should do exactly what I want, split an audio file on silent parts.
  However I can't seem to actually get it to export.
  While debugging i found that it doesn't seem to get into the for loop. When I put the for loop in a try except and print the exception, i get an expection saying "start".
  Could someone point me in the right direction?</p>
  
  <p>Thanks a lot!</p>