Patent · US Expired

Selectively activated dual tone multi-frequency detector

US5459781A · kind A · utility

30Cited by
18References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 12, 1994
Grant dateOct 17, 1995
Priority date
Expiry dateJan 12, 2014

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04M3/533
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A technique for improved DTMF detection utilizes a speech detector, either alone or in combination with other information from a voice processing arrangement, to adjust the sensitivity of the DTMF detector. The DTMF detector is turned completely off when the voice processing application is in the record mode, and when speech is detected.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.