DEVICE AND METHOD FOR SUPPRESSING NOISE SIGNAL, DEVICE AND METHOD FOR DETECTING SPECIAL SIGNAL, AND DEVICE AND METHOD FOR DETECTING NOTIFICATION SOUND

Provided is a noise signal suppressing device including: an input unit configured to receive a sound signal; a time/frequency converting unit; an independent peak spectrum extracting unit configured to extract a peak spectrum having independence; a persistence determining unit configured to determine that the peak spectrum having independence persists for a predetermined period or longer; a noise-signal suppressing unit configured to suppress the peak spectrum having independence as the noise signal. The independent peak spectrum extracting unit includes: a first peak extracting unit configured to extract a peak spectrum having higher energy than that of an adjacent frequency signal, and a second peak extracting unit configured to extract a peak spectrum maintaining a frequency interval of equal to or larger than a predetermined value with respect to a peak spectrum adjacent thereto as the peak spectrum having independence.