Method and apparatus for speech analysis
US4817155A · kind A · utility
Inventors
Key dates
| Filing date | Jan 20, 1987 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Jan 20, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L15/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Speech analysis is performed by synchronizing, with the initiation of glottal pulses produced during the voicing of phonemes, a pitch-independent transform that performs analysis entirely within a pitch period. Analysis is made of the three most dominant formant frequencies of the sound sets involved in the enunciation of voiced phonemes. Peaks in the transform represent formant frequencies. Three peaks are selected from the transform identifying the frequencies with the first, second and third greatest amplitudes. Correlation of the waveform between successive pitch periods detects whether a sound is a vowel, a voiced sibilant, or unvoiced. Unvoiced sound sets are similarly analyzed but the analysis is synchronized with artificially generated synch pulses. The sound sets are analyzed to determine (1) whether the sound is a vowel, a voiced sibilant or an unvoiced sound; (2) the primary formant frequency, i.e. the one with the greatest amplitude; (3) the substantial presence of secondary and tertiary formant frequencies with the next two largest amplitudes, as well as their frequencies; (4) the frequency ratios of the primary to the secondary and the primary to the tertiary frequenc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.