Autoplay doesn’t work for embeded audio file

Hi there, maybe someone can help me? I followed the F.A.Q. instructions on how to install the audio player and everything worked fine. Then I wanted to enable "autoplay" and "loop" but it only works in that way while I am logged in. When a visitor enters the site "autoplay" doesn't start, the "loop" works though. Please does anyone know what could be the problem? I would really appreciate your help. Kind regards Lavinia