var url : String;
function Start () {
var www = new WWW(url);
audio.clip = www.audioClip;
}

function Update () {
if(!audio.isPlaying && audio.clip.isReadyToPlay)
audio.Play();
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
public string url;
void Start() {
WWW www = new WWW(url);
audio.clip = www.audioClip;
}
void Update() {
if (!audio.isPlaying && audio.clip.isReadyToPlay)
audio.Play();

}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public url as string

def Start():
www as WWW = WWW(url)
audio.clip = www.audioClip

def Update():
if (not audio.isPlaying) and audio.clip.isReadyToPlay:
audio.Play()