| 摘要 |
PROBLEM TO BE SOLVED: To provide a noise eliminating device which erases noise even at sections where sound and noise are mingled and cause no deterioration of sound quality. SOLUTION: This noise eliminating device has a FFT(Fast Fourier Transform) circuit, an inverse FFT circuit and a noise estimating circuit that estimates noise spectrum, eliminates noise by transforming input signals to a frequency spectrum region and estimates and subtracts the noise spectrum. It is provided with a sound detecting circuit 6 which detects sound in a time region, a noise level detecting circuit 5 which detects noise level, and an adding (subtracting) circuit 9. The circuit 5 detects the noise level of the section where input signals are judged to be noise by the circuit 6. The amplitude at each frequency of the above noise spectrum is averaged in terms of speed in accordance with the above noise level and converted to a time region by the inverse FEET circuit 8. The above noise signals are subtracted from the input signals by the adding (subtracting) circuit 9 to elimnate noise. |
