The guys at Hackedgadgets.com grew wary of fickle alarm clocks that do little to wake them up and are fed up with the weak ringing of standard alarms. The solution was simple: create a louder alarm clock. They accomplished this goal by hooking up a standard alarm clock mechanism to a fire alarm bell. Standard alarm clocks use a “piezo buzzer”, however a fire alarm is quite louder than that. All that was required for this project was an alarm clock, a fire alarm and a coat hanger (to make it stand up). They simply took the signal from the circuit board and routed it into the interface board of the fire alarm. The link below has step by step instructions on how to recreate the project.- Wyatt Berkover
http://hackedgadgets.com/2008/01/11/fire-alarm-bell-alarm-clock-worlds-loudest-alarm-clock/