So for the last three months I have been hearing a sound like the clicking of a camera shutter or a screenshot sound in random places. For example, in a campsite far from the highway in broad daylight, or while I'm alone in my apartment or when I'm just minding my own business doing one of my hobbies or while at work.

I'll even hear it when I'm out and about too, like in Walmart restaurants and other places with lots of sound. I would expect there to be such a sound in places like these but the thing that sort of troubles me is I haven't noticed it until 3 months ago and it's the same exact sound every time at the same volume, always sounds like it's more than 5 feet away and I've noticed it happens the most when my environment is quiet or if I'm focused on something.

When I hear it I stop what I'm doing and take a quick glance around to see if anyone is using a camera or holding their phone like they're taking a picture to justify the sound but ever since the sound started , I haven't been able to pinpoint it to anyone or anything that I can see.

As far as I'm aware no one else around me hears these noises so I don't have any witnesses. I would like answers and\or advice on my situation.

Am I going crazy from the stress of life? Could I be developing schizophrenia? Or some kind of animal like a bat or something? Or am I just not getting enough sleep? I don't do drugs or take medication. These are just a few of the questions that are running through my mind I just can't seem to find an explanation for it.