audioNotification.user.js

// ==UserScript==
// @name     Test Script 275457
// @version  1
// @include *example.com/*
// @grant GM.getResourceUrl
// @require https://greasemonkey.github.io/gm4-polyfill/gm4-polyfill.js
// @require https://raw.githubusercontent.com/lodash/lodash/4.17.5/dist/lodash.min.js
// @resource soundA https://raw.githubusercontent.com/KDE/oxygen/master/sounds/Oxygen-Im-Contact-In.ogg
// @resource soundB https://raw.githubusercontent.com/KDE/oxygen/master/sounds/Oxygen-Sys-Special.ogg
// ==/UserScript===

/**
 * Settings
 */

const notificationFrequency = 45000;


/**
 * Add a button for toggling sound notifications and create click handlers
 */

const enableSound = () => {
  makeSound = _.throttle(makeSoundFunc, notificationFrequency, { leading: true, trailing: false })
  const button = document.getElementById('toggle-btn');
  button.onclick = () => {
    disableSound();
  }
  button.innerHTML = "Disable audio notifications"
}

const disableSound = () => {
  makeSound.cancel()
  makeSound = _.throttle(makeSoundFunc, Infinity, { leading: false, trailing: true })
  const button = document.getElementById('toggle-btn');
  button.onclick = () => {
    enableSound();
  }
  button.innerHTML = "Enable sound notification"
}

const buttonStyle = "position:absolute; top:0px; right:0px";
const toggleButton = document.createElement('button');
toggleButton.onclick = enableSound;
toggleButton.setAttribute('id', 'toggle-btn');
toggleButton.innerText = 'Enable sound notifications';
toggleButton.setAttribute('style', buttonStyle);
document.body.appendChild(toggleButton)


/**
 * Create buffers with the audio files
 */
const getBuffer = (url) => {
  const ctx = new AudioContext();
  return fetch(url).then(res => res.arrayBuffer())
    .then(res => {
    	const buff = ctx.decodeAudioData(res)
			ctx.close();
    	return buff;
  })
}


let aBuff, bBuff;

(async function () {
  const sndAUrl = await GM.getResourceUrl('soundA');
  const sndBUrl = await GM.getResourceUrl('soundB');
  aBuff = await getBuffer(sndAUrl);
  bBuff = await getBuffer(sndBUrl);
})()

/**
 * makeSoundFunc takes a buffer of audio data and plays it through the previously created AudioContext
 */

const makeSoundFunc = (buffer) => {
  console.log('duration: ' + buffer.duration);
  const ctx = new AudioContext();
  console.log('makeSoundFunc invoked')
  const source = ctx.createBufferSource();
  source.buffer = buffer;
  source.connect(ctx.destination);
  source.loop = false;
  source.start(0);
  
  setTimeout(() => {
    ctx.close()
  }, Math.floor(buffer.duration * 1000))
}

let makeSound = _.throttle(makeSoundFunc, Infinity, { leading: false, trailing: true });


function checkOpen() {
    makeSound(aBuff);
}

setInterval(checkOpen, 100);