Type: Technique</p></section><section class="applicability"><h2>When to Use</h2>
      <p>Any technology that supports audio and video.</p>
   </section><section class="description"><h2>Description</h2>
      <p>The objective of this technique is to provide a second version of video content that provides audio desciptions so that it is possible for people who cannot see to be able to understand audio-visual material.</p>
      <p>Since most user agents today cannot merge multiple sound tracks, this techniqu