I keep hearing beeping ... can anyone help explain?

Hello, I am new here. I came here because I am desperate to try and find out why I keep hearing beeping or short buzzing noises from anything around me that seems to have a speaker like device. So far no one else in my family is experiencing it. But, thank goodness, they can also hear it so at least I know I am not looney!

It seems to have started about a week or two ago or so. The first time I heard it was from one of those "sound" machines; the kind you use to drown out other noises. I had it on upstairs in my bedroom so I could sleep. When I heard it, I just turned the thing off and it stopped. Then I used it again a couple of nights later and the same thing happened so I thought the machine was defective and thought no more of it. A couple of days later, I was driving downtown and I heard the very same sound from my radio! But, not being an alarmist type, I figured it was some weird interference going on perhaps in my area.

A day or so after that, I heard the sound again on my tv. Okay, so now it was getting a little strange. I had never heard this sound before and now I was hearing it every two days or so and in different places at different times. So far no one else had heard it. Then last night I heard it from my computer speakers. I began to doubt my sanity because once again no one was around to hear it.

So, today I brought my sound machine downstairs and plugged it in while I worked at my computer all day. I was determined to find out what the noise was. No noise... but, then it started again on my computer speakers. While it was still beeping, my daughter called on the phone and I could hear it on my phone's earpiece. I asked her if she could hear it but she couldn't. So now I was wondering if maybe something was wrong with my hearing or something.

Well, thank goodness, when my husband came home for lunch, he actually got to hear the noise on my computer speakers! Hallelujah! I am not crazy! After he left, the sound machine began beeping loudly and even clicking. I called him right away and he heard it over the phone. Then my daughter called back a bit later and the noise was on my phone and on the computer speakers again.

My husband just came in just now while I plugged in the sound machine again and the beeping started right up! I thought it sounded a bit like morse code but he learned mc in the Navy and says he doesn't remember it sounding like that. Any ideas what it could be? Btw, he said he heard it at work -- three block away from our house -- on his headphones for the first time today. So, now we know it isn't just around me... This is so strange.