| 摘要 |
PURPOSE:To easily specify a report originating position by providing a transmitter for transmitting sound waves modulated by an identification code, a receiver for outputting sound pressure data and the identification code and a position display circuit for analyzing the position of the transmitter and displaying the position. CONSTITUTION:Moving through plural floors, the sound waves modulated by the identification code are transmitted from a sound wave transmitter 1. The sound waves are received by plural sound wave receivers 11 appropriately arranged for the respective plural floors and the sound pressure data are generated from a reception level and are outputted to the position display circuit 21 along with the identification code through a transmission line L1. The identification code and the sound pressure data inputted to the circuit 21 are analyzed in the analysis circuit 22 of the circuit 21 and the identification code and the position of the receiver 11 for which sound data are excellent are displayed at a display 22. Thus, by using the sound waves for which a propagation route is shorter compared to radio, the transmission of an alarm sound and the specification of the originating position of an emergency report are facilitated. |
