Methods and apparatus for detecting voice information in telephone-type signals
US5239574A · kind A · utility
34Cited by
3References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1990 |
| Grant date | Aug 24, 1993 |
| Priority date | — |
| Expiry date | Dec 11, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M2201/40
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Voice signal information in a telephone-type signal is detected by subjecting the signal to several tests such as a minimum energy test, an amplitude ratio test, and a sequencing test which ensures that the other tests have been satisfied for a sufficient length of time and/or sufficiently frequently over a predetermined time interval. A voice processing system such as a voice mail system may use the detection of voice as above to initiate the transmission of an announcement or message during an automatically placed telephone call.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.