SteamVR & Steam Audio / Phonon

Hi !
I am working on an application using Unity & SteamVR and I would like to use Steam Audio.
I can create the audio configuration with Phonon Sources/Phonon Listener/Phonon manager settings but when I go from one scene to another (each one has been configured independently with Phonon) sometimes Unity "freezes" and no way to get the loaded scene. No error is returned. Sometimes is loading but sounds are not played at all .
I tried to delete my phonon geometry (thinking it was the phonon geometry on a terrain which may generate issues) but no way to avoid the loading issue (loading done using SteamVR_LoadLevel script).
I would be grateful if you can help me .. any idea ?

NB : the package is the last one downloadable on Steam Audio webpage.