Load:
      <h1 aria-atomic="true" id="live"aria-live="polite">foo</h1>
      <button id="go">go</button>
      <script>
        document.getElementById('go').addEventListener('click', function(e) {
          document.getElementById('live').innerText = 'bar';
        });
      </script>

- click the button

result:
there are separate events for text changes to
- static text
- heading

There should be one event that updates both of these nodes.