Speech analyzer comprising circuits for calculating autocorrelation coefficients forwardly and backwardly
US4282405A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 1979 |
| Grant date | Aug 4, 1981 |
| Priority date | — |
| Expiry date | Nov 26, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/93
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A speech analyzer with improved pitch period extraction and improved accuracy of voiced/unvoiced decision comprises circuits for calculating autocorrelation coefficients forwardly and backwardly with respect to time. Reference members for the forward and the backward calculation are those successively prescribed ones of windowed samples of a signal representative of speech sound which are placed in each window period farther from a trailing and a leading end thereof, respectively. Members to be joined to the respective reference members for forward and backward calculation of each autocorrelation coefficient are displaced therefrom by a joining interval farther from the leading and the trailing ends, respectively. The joining interval is varied between a shortest and a longest pitch period of the speech sound stepwise by a spacing between two successive windowed samples. One of the joining intervals for which the greatest of the autocorrelation coefficients is calculated during each window period gives a better pitch period for that period than ever obtained. The circuits may comprise a circuit for calculating a rate of increase of an average power of the speech sound in each windo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.