If your application works with audio and video (for example, you're developing a video conferencing service), it would be probably a good idea to add a live indication of the microphone sound level. Using this feature, peers can estimate and control their microphone's audio levels. So, in this recipe, we're implementing microphone activity indication.
This recipe is simple, and you will just need a text editor to create and edit HTML. To test this recipe, you should have a web server installed and configured—it is highly recommended to test the example via a web server rather than just on a local filesystem; otherwise, the web browser might block calls to the WebRTC API.