Remove suggestion to "duck" less-important audio/dialogue

Author: patrickhlauke

understanding/20/audio-description-or-media-alternative-prerecorded.html

@@ -22,10 +22,8 @@ <h2>Intent of Audio Description or Media Alternative (Prerecorded)</h2>
          augments the audio portion of the presentation with the information needed when the
          video portion is not available. Audio description provides information about actions,
          characters, scene changes, and on-screen text that are important and are not described
-         or spoken in the main sound track. Audio description is usually added during existing
-         pauses in dialogue. In rare cases where the original audio does not provide sufficient
-         pauses, it may be possible to create them by lowering the volume ("ducking") some of the
-         existing dialogue, if the need for audio description is deemed to be more important.
+         or spoken in the main sound track. Audio description is added during existing
+         pauses in dialogue.
       </p>
 
       <p>The second approach involves providing all of the information in the synchronized

understanding/20/audio-description-prerecorded.html

@@ -18,10 +18,8 @@ <h2>Intent of Audio Description (Prerecorded)</h2>
          audio description augments the audio portion of the presentation with the information
          needed when the video portion is not available. Audio description provides information about actions,
          characters, scene changes, and on-screen text that are important and are not described
-         or spoken in the main sound track. Audio description is usually added during existing
-         pauses in dialogue. In rare cases where the original audio does not provide sufficient
-         pauses, it may be possible to create them by lowering the volume ("ducking") some of the
-         existing dialogue, if the need for audio description is deemed to be more important.
+         or spoken in the main sound track. Audio description is added during existing
+         pauses in dialogue.
       </p>
 
       <div class="note">