title: The notification sound does not want to shut down by hardware key
body: <p>"I'm making iOS alarm application.</p>
  
  <p>currently it's proceeded through UILocalNotification.</p>
  
  <p>but when alarming on scheduled time, I want to stop alarming only in the application.
  app is backgrounded.
  generally when alarming through UILocalNotification, it's possible to kill the alarm sound as hardware key. 
  what should I do? </p>
  
  <p>help ~~ </p>