Voiced/unvoiced decision using a plurality of sigmoid-transformed parameters for speech coding
US6023671A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1997 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | Apr 11, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L25/93
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for voiced/unvoiced decision for judging whether an input speech signal is voiced or unvoiced. The input parameters for performing the voiced/unvoiced (V/UV) decision are comprehensively judged in order to enable high-precision V/UV decision by a simplified algorithm. Parameters for the voiced/unvoiced (V/UV) decision include the frame-averaged energy of the input speech signal lev, the normalized autocorrelation peak value r0r, the spectral similarity degree pos, the number of zero crossings nZero, and the pitch lag pch. If these parameters are denoted by x, these parameters are converted by function calculation circuits using a sigmoid function g(x) represented by EQU g(x)=A/(1+exp (-(x-b)/a)) where A, a, and b are constants differing with each input parameter. Using the parameters converted by this sigmoid function g(x), the voiced/unvoiced decision is made a V/UV decision circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.