Method and system for improving speech recognition through front-end normalization of feature vectors
US5604839A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1994 |
| Grant date | Feb 18, 1997 |
| Priority date | — |
| Expiry date | Jul 29, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L15/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and system for improving speech recognition through front-end normalization of feature vectors are provided. Speech to be recognized is spoken into a microphone, amplified by an amplifier, and converted from an analog signal to a digital signal by an analog-to-digital ("A/D") converter. The digital signal from the A/D converter is input to a feature extractor that breaks down the signal into frames of speech and then extracts a feature vector from each of the frames. The feature vector is input to an input normalizer that normalizes the vector. The input normalizer normalizes the feature vector by computing a correction vector and subtracting the correction vector from the feature vector. The correction vector is computed based on the probability of the current frame of speech being noise and based on the average noise and speech feature vectors for a current utterance and a database of utterances. The normalization of the feature vector reduces the effect of changes in the acoustical environment on the feature vector. The normalized feature vector is input to a pattern matcher that compares the normalized vector to feature models stored in the database to find an exact ma…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.