One of the psychological diseases du jour is called Ringxiety: that's when "patients" think they hear their phone ring or feel their phone's vibration when it's not really ringing or vibrating. That's right, just the "phantom ringtone" repackaged as a "psychological disease." Article [1]
Links:
[1] http://www.techgadgets.in/mobile-phones/2007/19/ringxiety-a-disease-found-in-extensive-mobile-phone-users/