The AC noise is fixed

Fingers crossed, I believe the very annoying noise that had bothered us nightly since we moved here on August 3(and even sometimes during the day) has finally been eliminated.  I was able to get a recording of the lovely sounds, even if the sounds quality was poor and softer than reality. When couple of technicians appeared after a phone call placed by Feriz (houseman) I played the recording for them. There was an "ah-ha" moment and they knew what it was: a filter was loose and was vibrating and causing the noise. It appears they successfully stopped the noise! I would attach a copy of the recording but it seems I can only attach photos and video to this blog. Sorry!