As the topic says - whenever I play voice briefing of my flight plan this is what I hear. i fly mostly in Europe. Should I be worried about this or its normal behaviour? 

Not sure I have heard one yet either, but I will try it out later.My understanding is that Sigmets are for severe turbulence /icing and  I believe cover an area of 3,000 miles if your fight plan passes it. I think it may also include things like volcanic ash as well. Airmets cover smaller areas with less severe turbulence/icing, sustained surface winds or widespread limited visibility. Not every flight plan will have them active. Also, I believe that you will not get them when using historical weather. Try flying with current weather and use the filtering engine to determine where there is currently severe turbulence and see if they pop up in your briefing then.   

Ok, I always fly real weather. Thank You for tips!