Background Audio Distorted during Scene loading

Hello,
In my landing scene, I have an audio source to play a background audio clip (DontDestroyOnLoad is set).
When the player selected some options, the main scene is loaded. 
The problem is that the background audio is distorted during the scene loading.
I tried the change the CPULevel to 4 during the loading but it doesn't fix it.
Any idea ?
Ric.