Before revision: Electromechanical bells have been widely used at railroad crossings, in telephones, fire and burglar alarms, as school bells, doorbells, and alarms in industrial plants , since the late 1800s, but they are now being widely replaced with electronic sounders.
After revision: Electromechanical bells have been widely used at railroad crossings, in telephones, fire and burglar alarms, as school bells, doorbells, and alarms in industrial area , since the late 1800s, but they are now being widely replaced with electronic sounders.