Patent ID: 8370137

Claim:
A noise estimating apparatus for estimating two types of noise spectra for removing a noise component using the two types of noise spectra, the apparatus comprising: an A/D converter that converts an input speech signal to a digital signal; a Fourier transformer that performs a discrete Fourier transform on the digital signal having a predetermined time length obtained by the A/D converter to obtain an input spectrum and a complex spectrum; a noise spectrum storage device that stores the two types of noise spectra including a mean noise spectrum for use in noise cancellation processing and a compensation noise spectrum for compensating for a spectrum of an over-reduced frequency in the noise cancellation processing; a noise estimator that estimates a new compensation noise spectrum and a new mean noise spectrum as new two types of noise spectra, the new compensation noise spectrum being obtained by comparing the input spectrum obtained by the Fourier transformer with the compensation noise spectrum stored in the noise spectrum storage device, the new mean noise spectrum being obtained by using the input spectrum obtained by the Fourier transformer in a learning algorithm, and stores the new two types of spectra in the noise spectrum storage device.