tton>
  </body>
  <script>
    const audioElt = document.querySelector("audio");
    const pre = document.querySelector("pre");
    const button = document.querySelector("button");
    let audioCtx;

    audioElt.addEventListener("play", () => {
      if (!audioCtx) {
        // Set up AudioContext
        audioCtx = new AudioContext();

        // Create a MediaElementAudioSourceNode
        // Feed the HTMLMediaElement into it
        const source = new MediaElementAudioSourceNode(audioCtx, {
          me