Just like electronic sirens, electronic public address systems are also devices designed for exterior and interior sound distribution. Unlike electronic sirens these systems have the output of the electronic amplifiers divided between several loudspeakers with lower output. The loudspeakers are therefore mounted closer to each other and are commonly connected to the amplifier via 100V distribution systems. The application of smaller outputs and a higher number of loudspeakers make it possible to improve notification clarity and coverage. On the other hand the costs of system establishment and maintenance increase substantially if the system is to cover larger areas. Mainly the lines are susceptible to failures, if they are not placed underground in a proper manner. Underground lines, however, would increase system establishment costs to an even greater extent.