iPhone gives alerts indiscriminantly
About a week ago my iPhone began to give indiscriminate alerts, CONSTANTLY! What's even more strange, the alert sound is not found on any of the alerts that my iPhone offers. It's a type of chime with three beats. It doesn't chime on the hour or around texts, voice mail, etc. Sometimes it will chime everytime ten plus minutes for three or four times. Then, nothing for three or four hours. Then one chime. I had to turn it off at night because it would start singing in the middle of the night. Help!
MacBook Pro, Mac OS X (10.6.8)