title: iOS - Notification of when a call is taking place?
body: <p>Is it possible to be notified or detect when a GSM/CDMA call is taking place on an iOS handset?</p>
  
  <p>I have an application that uses audio in the background and I want to be able to detect when a call is taking place so that my app can react accordingly so as not to intrude on the cellular call in anyway.</p>
  
  <p>Essentially I want to be able to detect when a call is taking place so that if the user enters my application while on a call I can disable some functionality.</p>
  
  <p>So I was wondering how I can detect that a cellular call is taking place on a device?</p>