sound not loading

hello
not sure why but sound urls from "Introduction to interactive programming in python" not working in my computer when i run my code 

ship_thrust_sound = simplegui.load_sound("http://commondatastorage.googleapis.com/codeskulptor-assets/sounddogs/thrust.mp3")
ship_thrust_sound.set_volume(1)
ship_thrust_sound.play()

i don't hear a sound
