Intercom extension chime

摘要

PROBLEM TO BE SOLVED: To provide an intercom extension chime in which the number of times of sounding is reduced by not performing the calling operation anew when there is a re-output in a given amount of time, even if the calling signal outputted from the extension speaker of an intercom apparatus is interrupted.SOLUTION: An intercom extension chime has an extension chime CPU31 for sounding a ringing tone by receiving input of a calling signal, and a sounding speaker 32. If the time until input of a next calling signal is within a specific time, the extension chime CPU31 determines that the calling is ongoing even if input of calling signal is interrupted, and does not sounds the ringing tone anew.SELECTED DRAWING: Figure 2