title: Detect and record a sound with python
body: <p>I'm using this program to record a sound in python:</p>
  
  <p><a href="https://stackoverflow.com/questions/892199/detect-record-audio-in-python/892293#892293">Detect &amp; Record Audio in Python</a></p>
  
  <p>I want to change the program to start recording when sound is detected by the sound card input. Probably should compare the input sound level in chunk, but how do this?</p>