High pitched noise in one area of house

In the last few weeks I started experiencing a very high pitch noise in one end of the house (only). I can only hear it with my right ear. My husband can't hear it at all. We have a 15 foot ceiling in the living room and the solar panels are above this ceiling. The electrical boxes are outside on the other side of the living room wall.  The power company was here and, of course, their guy could not here it. I can hear it even when the main breaker is shut off. It is very disturbing to me and I really think I am going crazy. I called the solar panel company and they can tell the panels are functioning and the guy seemed to poopoo my idea that maybe it was an inverter. They will of course send someone for the $90+ an hour. My next step is to find someone that has an iphone app called "Mosquitone Detector".  Has anyone out there ever heard of this issue? 

My advice would be to get some kids in - they will hear it clearly if its there

Have you switched the inverter off? Does that make a difference? 

some solar inverters will make  a high pitched whine, but obviously not at night! 

Thank you for your suggestions. I appreciate the feedback. After this C-virus is over maybe I will borrow someone's kid. They will hear it