My audio.Play wont play outside function Update

i have this code that should start/stop my sound file when the rigidbody is/is not moving. I have succesfully made my booleans trigger from this but my sound wont play. What am i missing here? thx!

var audioPlayed : boolean = false;

function Update()
 {

              if(!rigidbody.IsSleeping())
              {

                  audioPlayed = true;

              }

              if(rigidbody.IsSleeping())
              {

                  audioPlayed = false;
              }


         }

         if(audioPlayed == true)
              {
                  audio.Play();
              }