You can not add an audio visualizer only by using HTML.
To do this you will need the Web Audio API in JS.
There are three main steps to add an audio visualizer to your webpage:
you need to create an audio element to play the sound
By using the API you analyze the audio frequencies
Use JS to update the graphics area in real time and display the visualization
Alternatively you can create a css-based visual effect that looks like a visualizer, but it will not actually react to the audio. This is a more simplefied way.