@Override
    public void initEvent(Application app, Cinematic cinematic) {
        super.initEvent(app, cinematic);
        audioNode = new AudioNode(app.getAssetManager(), path, stream ? AudioData.DataType.Stream : AudioData.DataType.Buffer);
        audioNode.setPositional(false);
        setLoopMode(loopMode);
    }
creates a sound event
used for serialization
jme3-core/src/main/java/com/jme3/cinematic/events/SoundEvent.java