| 摘要 |
PROBLEM TO BE SOLVED: To provide a noise suppressing device that can bring about a noise suppression favorable for hearing and that is little in deterioration of quality in a voice communication system, a speech recognition system or the like used under various noisy environment. SOLUTION: A time-frequency conversion means analyzes an input signal for every frame and converts it into an amplitude spectrum and a phase spectrum; on the basis of the result of a noise likeness of the input signal frame judged by a noise likeness analysis means, a noise amplitude spectrum calculating means calculates the noise amplitude spectrum by using the input amplitude spectrum of the frame; a spectrum correction gain calculating means calculates a noise amplitude spectrum correction gain and a noise removal spectrum correction gain by using the respective prescribed coefficients of the input amplitude spectrum and the noise amplitude spectrum; a spectrum subtracting means multiplies the noise amplitude spectrum by the noise amplitude spectrum correction gain, and substrates the product from the input amplitude spectrum to output a 1st noise removed spectrum; a spectrum amplitude suppression means multiplies the 1st noise removal spectrum by the noise removal spectrum correction gain and outputs a 2nd noise removal spectrum; and the frequency-time conversion means converts it into a time base signal. |
