Distance measure in a speech recognition system for speech recognition using frequency shifting factors to compensate for input signal frequency shifts
US6032116A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1997 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | Jun 27, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L15/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
One embodiment of a speech recognition system is organized with speech input signal preprocessing and feature extraction followed by a fuzzy matrix quantizer (FMQ). Frames of the speech input signal are represented by a vector .function. of line spectral pair frequencies and are fuzzy matrix quantized to respective a vector .function. entries in a codebook of the FMQ. A distance measure between .function. and .function., d(.function.,.function.), is defined as ##EQU1## where the constants .alpha..sub.1, a.sub.2, .beta..sub.1 and .beta..sub.2 are set to substantially minimize quantization error, and e.sub.i is the error power spectrum of the speech input signal and a predicted speech input signal at the ith line spectral pair frequency of the speech input signal. The speech recognition system may also include hidden Markov models and neural networks, such as a multilevel perceptron neural network, speech classifiers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.