Silence editing speech processor
US4449190A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1982 |
| Grant date | May 15, 1984 |
| Priority date | — |
| Expiry date | Jan 27, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B14/068
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In an ADPCM system, improved detection of silence intervals in a speech signal is attained by detecting the level of the logarithm step-size signal (d.sub.n), which is representative of the energy of the speech samples. A speech pattern is converted into a sequence of adaptive digital codes. Intervals of silence in the pattern are detected and a digital code representative of each silence interval is generated. The adaptive digital codes and the silence interval codes are combined to form a digitally coded signal representative of the pattern. The conversion of the pattern to adaptive digital codes includes forming a signal corresponding to the adaptation step-size for each digital code. The silence interval detection includes producing first and second threshold signals. A silence interval signal is initiated when the adaptation step-size corresponding signal diminishes below the first threshold and the silence interval is terminated when the adaptation step-size corresponding signal increases above the second threshold after the silence interval initiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.