Tampermonkey extension to speed up or slow down Whatsapp Web audios

zapzap-audio-speed.js

// ==UserScript==
// @name         WhatsApp Audio Playback Rate Changer
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://web.whatsapp.com/
// @grant        none
// @runat        document-end
// ==/UserScript==

(function() {
    'use strict';
    var playbackRate = 1;

    var changeAudioPlaybackRate = function(){
        document.querySelectorAll('audio').forEach(audio => audio.playbackRate = playbackRate);
    }

    document.addEventListener('keydown', function(){

        if (event.altKey){
            if (event.key == '+') {
                playbackRate += .25;
                changeAudioPlaybackRate();
            } else if (event.key == '-') {
                playbackRate -= .25;
                changeAudioPlaybackRate();
            }
        }
    });

    const RECEIVED_AUDIOS_WHATSAPP_SRC = 'blob:https://web.whatsapp.com/'
    const audioDefaultPlay = window.Audio.prototype.play

    window.Audio.prototype.play = function(){
        if (this.src.startsWith(RECEIVED_AUDIOS_WHATSAPP_SRC)){
            this.playbackRate = playbackRate;
        }

        audioDefaultPlay.apply(this)
    }
})();