nnwhen.com/res/asset-js-audio.js

function onlyPlayOneIn(container) {
  container.addEventListener(
    "play",
    function (event) {
      audio_elements = container.getElementsByTagName("audio");
      for (i = 0; i < audio_elements.length; i++) {
        audio_element = audio_elements[i];
        if (audio_element !== event.target) {
          audio_element.pause();
        }
      }
    },
    true
  );
}

function renderJSButtons() {
  // If JS is disabled this won't run and therefore JS-powered buttons won't be displayed
  let blockToggle = document.getElementsByClassName("block-toggle");
  for (let i = 0; i < blockToggle.length; i++) {
    blockToggle[i].style.display = "block";
    // Accessibility is important!!!
    blockToggle[i].ariaHidden = "false";
  }
}

function blockToggle(id) {
  var blockID = document.getElementById(id);

  if (blockID.style.display === "block") {
    blockID.style.display = "none";
    blockID.ariaHidden = "true";
  } else {
    blockID.style.display = "block";
    blockID.ariaHidden = "false";
  }
}

document.addEventListener("DOMContentLoaded", function () {
  onlyPlayOneIn(document.body);
  renderJSButtons();
});