title: Sox - concating multiple files with added padding between each
body: <p>I am new to Sox and was unable to find a way to do this so I'll be specific.</p>
  
  <ul>
  <li>I use Windows 7</li>
  <li>I have a batch of 94 .au files, each containing a spoken sentence (from the text of a language learning tool). They're named 00.au, 01.au, etc.</li>
  <li>I can concat them easily with sox with just the following: sox.exe *.au complete.wav</li>
  <li>The finished file plays them all in order and so far so good, but the original files have all silence between sentences removed, which means that sentence 2 starts immediately after sentence 1 etc., giving a very rushed and unnatural sound, and it's hard to follow.</li>
  <li>I have tried some variations on the pad command but without success. What I would love to do is concat the files, while adding 0.5 seconds of silence between EACH original .au file</li>
  </ul>
  
  <p>Does anyone know if this is possible, either with a script or by just one clever line? I don't understand the pad or delay enough.</p>