create-howl-node.js

import { Howl } from 'howler/src/howler.core';

export default function createHowl(src, onEnd) {
  return new Promise(function(resolve, reject) {
    const howl = new Howl({
      autoplay: false,
      onend: onEnd,
      src: [src],
      onload() { resolve(howl) },
      onloadeerror: reject
    });
  });
}

nodes.js

import createNode from './create-howl-node';

const nodes = {};

export function load({id, src, onEnd}) {
  return createNode(src, onEnd)
    .then(node => nodes[id] = node)
    .then(node => ({
      duration: node.duration()
    }));
}

export function pause(id) {
  nodes[id].pause();
}

export function play(id) {
  nodes[id].play();
}

export function stop(id) {
  nodes[id].stop();
}