A little while ago I realized that my cellphone ring was taking over my brain. It may be that I'm just overly sensitive to music, but I've come to the conclusion that the whole melodies-as-ringtones thing wasn't the greatest idea in the world. At least not for me and my phone.
First, I found myself occasionally noticing musical notes that matched the beginning of one of the melodies my phone uses. I don't have perfect pitch, but I apparently have enough pitch memory to set off associations sometimes. This resulted in periodic, split-second jolts of "oh-my-phone-is-ringing-oh-no-it's-not!" at the beginning of random songs, other people's cell phone rings, etc.
After that, I started being more aware of the part of my brain that's always scanning for my specific ring tone. If I left the TV on and go into another room, something was still picking up faint individual notes from the commercials and promoting them to brief moments of attention, in case they turned out to be from my phone. (Interestingly, though, regular music I was deliberately playing didn't have the same effect, perhaps because I was already consciously following a known melody.) Sometimes I would carry my phone with me from room to room, even though I knew I could hear it fine if it actually rang in another room, just to shut up that part of my mind that's out scouting for it.
Anyway, this all finally got annoying enough that I went and changed everything on my phone to real, honest-to-goodness ringing sounds, like a proper phone. And I must say it's been kind of a relief. My phone doesn't ring often enough to re-train me very quickly, but it doesn't have to. I know it won't be playing a melody at me when it does ring, so the musical part of my brain can relax and go back to it's normal job. Ahhhhh....