Audio Big Delay in the play one shot on click function

i am developing a pc game and added an onclick function to the play button (playoneshot) .... and added the sound source and added the sound clip and it is working but their is about 1500 millisecond delay which is not acceptable and also this is a scene loader button so this delay leads to that the sound never plays because the scene loads before the sound is played

 

Have you tried to preload the sound? I guess the problem is that the sound isn't loaded when you give the command to play so it starts loading and your scene has loaded in sooner than the sound.
See Preload Audio Data.