title: How to detect voice in my iPhone app?
body: <p>I want to fire some method on voice detection.</p>
  
  <p>For Example,</p>
  
  <p>Just like in <code>PragDuck</code> app, When user starts speaking <code>duck</code> starts its animation. </p>
  
  <p>How can I detect users voice?</p>