title: Mute Voice Directions in Here Maps iOS SDK
body: <p>I want to toggle the voice directions in my iOS app between on and off. The HERE maps instructions (<a href="https://developer.here.com/mobile-sdks/documentation/ios-hybrid-plus/topics_api_nlp_hybrid_plus/protocolnmaaudiomanagerdelegate-p.html" rel="nofollow noreferrer">https://developer.here.com/mobile-sdks/documentation/ios-hybrid-plus/topics_api_nlp_hybrid_plus/protocolnmaaudiomanagerdelegate-p.html</a>) are still all in objective-C. It is quite clear in that language how to do this, but I am looking for the Swift 3 equivalent. That manual says:</p>
  
  <blockquote>
    <ul>
    <li>@optional (BOOL) audioManager:( NMAAudioManager *) audioManager shouldPlayOutput:( NMAAudioOutput *) output</li>
    </ul>
    
    <p>Called when the audio manager has output to play.</p>
    
    <p>If the delegate returns YES, or the delegate does not implement this
    method, the output is played immediately. If the delegate returns NO,
    the delegate takes over responsiblity for handling the output.</p>
  </blockquote>
  
  <p>I am guessing something similar to this, but I can't get it right:</p>
  
  <pre><code>func audioManagerShouldPlayOutput(_ audioManager: NMAAudioManager!, shouldPlayOutput:false) {
      }
  </code></pre>