SPEECH ARTICULATION IMPROVING DEVICE AND NOISE LEVEL ESTIMATION METHOD THEREOF

PROBLEM TO BE SOLVED: To provide "a speech articulation improving device and a noise level estimation method thereof" in which even when noise level abruptly varies, a suitable correction gain can be set. SOLUTION: When the noise level is in a stationary state, a switch 15 is switched to the side of a terminal (a) so as to output an average value of the noise level calculated by an averaging processing section 12 as a current estimated noise level, and when a determination processing section 14 detects that difference between an instantaneous value of the estimated noise level and the average value thereof is larger than a threshold continuously for a predetermined time, the switch 15 is switched to the side of a terminal (b) so as to output the instantaneous value of the noise level as a current estimated noise value. Thus, when the noise level abruptly varies, the estimated noise level output from a noise level estimation section 7 to a gain correcting section 8 can be switched from the average value to the instantaneous value, so that follow-up ability of noise level estimation in the abrupt variation in noise level can be enhanced. COPYRIGHT: (C)2008,JPO&INPIT