Patent · US Expired

Gain switched audio conferencing network

US4716585A · kind A · utility

86Cited by
130References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 5, 1985
Grant dateDec 29, 1987
Priority date
Expiry dateApr 5, 2005

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N7/15
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An audio conferencing system includes a plurality of remote stations (10) which are interconnected in a conference mode through a central switching network (66) through communication lines (16). Each of the remote stations has a microphone (34) and a speaker (64) associated therewith. The microphone (34) on each of the remote stations has a voltage controlled amplifier (VCA) (59) associated therewith and the speaker (64) has a VCA (60) associated therewith. A CPU (48) selectively controls the output of the microphone (34) to selectively decrease the gain thereof when voice is not detected. When voice is detected above a predetermined threshold, the microphone (34) is allowed to operate at full gain and the speaker (64) has the output level thereof decreased. This effectively reduces the audio loop gain between remote stations in a conference.

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