Clattering noise - Me being too sensitive?

I contacted Wahoo Support and they could not help me yet. After having a problem with vibration while riding, another problem occured, or at least it is a sound/noise I have not heard before or have not paid attention to yet. 

I added two links of videos I made. You can hear the usual Kickr sound but then there is a kind of “clattering” sound “underneath” it if you listen carefully.


Is that normal and I am just being over-sensitive? Or is there something wrong?