title: How to stop Text to Speech when Voiceover is speaking, or vice versa in Swift?
body: <p>Right now, my app implements <code>AVSpeechSynthesizer</code> to read out instructions for each screen. The app also takes into consideration when Voiceover accessibility feature is enabled. </p>
  
  <p>The problem I'm facing now is that the text to speech feature overlaps with the voiceover feature. Is there a solution to detect that when a user navigates to another element on the screen, TTS stops speaking, or when TTS is speaking, voiceover doesn't speak until TTS finishes (the former is preferred though).</p>
  
  <p>The current development is on iOS 8, using Swift.</p>