Abstract: A speech recognition apparatus includes a feature extraction section, and a recognition section. The feature extraction section extracts the feature vectors of input speech. The feature extraction section includes at least a pitch intensity extraction section. The pitch intensity extraction section extracts the intensities of the fundamental frequency components of the input speech. The recognition section performs speech recognition by using the feature vectors from the feature extraction section.

Abstract: A method for reducing noise in a speech signal by controlling suppression of a predetermined band when an input speech signal has a large pitch strength. The noise reduction method is to be used in an apparatus having a signal characteristic calculating unit, an adjustment calculating unit 32, a consonant component valve (CE) and relative noise level value calculating unit, a prefilter or Hn value calculating unit, and a spectrum correcting unit as main components. The signal characteristic calculating unit derives a pitch strength of the input speech signal. The adjustment calculating unit derives an adjustment value according to the pitch strength. The CE and NR value calculating unit derives an NR value according to the pitch strength. Then, the Hn value calculating unit derives the Hn value according to the NR value and sets a noise suppression rate of the input speech signal. The spectrum correcting unit 10 reduces the noise of the input speech signal based on the noise suppression rate.