title: How do I change the volume of a PCM audio stream in node?
body: <p>I am trying to figure out how to adjust the volume level of a PCM audio stream in node.</p>
  
  <p>I have looked all over npmjs.org at all of the modules that I could find for working with audio, but haven't found anything that will take a stream in, change the volume, and give me a stream out. </p>
  
  <p>Are there any modules that exist that can do this, perhaps even even something that wasn't made specifically for it?
  If not, then I could create a module, if someone can point me in the right direction for modifying a stream byte by byte.</p>
  
  <p>Here is what I am trying to accomplish:
  I am writing a program to receive several PCM audio streams, and mix them for several outputs with varying volume levels. Example:</p>
  
  <pre><code>inputs       vol    output
  
  music        25%    output 1 
  live audio   80%    output 1
  microphone    0%    output 1
  
  music       100%    output 2 
  live audio    0%    output 2
  microphone    0%    output 2
  </code></pre>