title: How to merge several audio files using sox
body: <p>I use this command to merge two audio files into one using sox:</p>
  
  <pre><code>sox end.mp3 -p pad 6 0 | sox - -m start.mp3 output.mp3
  </code></pre>
  
  <p>I was wondering how can I merge 3 or 4 audio files using only one command instead of using the "output.mp3" as the input to the next command and so on?</p>
  
  <p>I will really appreciate any help</p>