rt.user.js

// ==UserScript==
// @name           HTML5 Audio for learnrussian.rt.com
// @namespace      Replaces flash audio on learnrussian.rt.com with HTML5 audio
// @include        http://learnrussian.rt.com/*
// @include        https://learnrussian.rt.com/*
// ==/UserScript==

document.querySelectorAll("div[audio]").forEach(function(x) {
  var audio = document.createElement("audio");
  audio.setAttribute("controls", "");
  var src = document.createElement("source");
  src.setAttribute("src", x.getAttribute("audio"));
  audio.appendChild(src);
  x.className = "";
  x.appendChild(audio);
});

document.querySelectorAll(".plpau").forEach(function(x) {
  x.remove();
});