Only I can hear the strange sound my A/C is making

I keep hearing this strange sound in the middle of the night.

It is so high pitched that, at first, I wasn’t sure I was really hearing it.

But it is definitely there. It sounds like a really high pitched whistle. I usually have the TV or my music on when I am home during the day. I guess that explains why I only hear the sound at night when I am trying to fall asleep. Sometimes, it even wakes me up when I am already asleep. At first, I thought it was my refrigerator making the noise. However, after a bit, I realized that it is my air conditioner. I only hear the whistling sound when the compressor is on. I went outside but I can’t hear the sound when I get up close to the air conditioner compressor. I think that the sound of the fans drowns it out or something. Maybe it can only be heard through the ductwork. I don’t know. I just worry that if I call for some HVAC service, the technician won’t even be able to hear the sound at all. After all, my wife can’t hear it. She says that the whistling sound is all in my head but I know it is there. I don’t want to waste money having an HVAC technician come out only to tell me that my HVAC system is fine and he doesn’t hear any strange noises. What if the sound really is all in my head? Or, maybe I just acquired super human hearing somehow. Maybe this sound is normal for the air conditioner and I just couldn’t hear it before.

 

Only I can hear the strange sound my A/C is making