To easily set a plurality of alarm sounds each having an intelligible alarm degree by the effective use of a narrow-band frequency.
The plurality of alarm sounds are allocated to alarm degree levels showing the alarm degrees, and a targets alarm degree index indexed with a target value of an attention arousing effect is associated to each alarm degree level. A characteristic map set with an alarm degree index is set to each of a frequency, a period, a repetition frequency and a sounding rate of the alarm sound. The map is set such that a total value of the alarm degree index obtained from at least the frequency characteristic map and the alarm degree index obtained from at least one other characteristic map satisfies the target alarm degree index corresponding to the alarm sound (alarm contents) to be set.
TAKAHASHI TATSURO
OSUGI IKUYO
