Line spectral frequencies and energy features in a robust signal recognition system
US6009391A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1997 |
| Grant date | Dec 28, 1999 |
| Priority date | — |
| Expiry date | Aug 6, 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 in a matrix by a vectorf of line spectral pair frequencies and energy coefficients and are fuzzy matrix quantized to respective vector f entries of a matrix codeword in a codebook of the FMQ. The energy coefficients include the original energy and the first and second derivatives of the original energy which increase recognition accuracy by, for example, being generally distinctive speech input signal parameters and providing noise signal suppression especially when the noise signal has a relatively constant energy over at least two time frame intervals. To reduce data while maintaining sufficient resolution, the energy coefficients may be normalized and logarithmically represented. A distance measure between f and f, d(f, f), is defined as ##EQU1## where the constants .alpha..sub.1, .alpha..sub.2, .beta..sub.1 and .beta..sub.2 are set to substantially minimize quantization error, e.sub.i is the error power spectrum of the speech input signal and a predicted speech input…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.