Emission timing controller by single board computer for public address system

The Great East Japan Earthquake revealed the Importance of a public address system with outdoor loudspeakers for emergency announcements and the difficulty of its intelligibility. To achieve a public address system with sufficient intelligibility for residents, one important factor is to suppress sound overlap caused by the simultaneous emission of other loudspeakers. In this paper, the controller of an emission timing control method is built with a single board computer. Functions to increase reliability of a public address system are also implemented to the controller.