Only a few years ago, adding an audio file wasn't that easy. Until the HTML5 release, there was no standard for defining embedded media such as audio in web browsers. Today, all you have to do is to insert the <audio> element and specify the file source with the src attribute or multiple file sources with the <source> element. Make sure to close the <audio> tag and put the </audio> at the end once you've specified the file location and audio properties.^[1]

The phrase "Audio not supported" between <audio></audio> will show up only when the browser has problems loading the file.