A device used to connect multiple parties over the phone. A proctor or operator can man conference bridges, or the can be supervised. There are both stand-alone conference bridges and conference bridge functions built in to some PBXs (Private Branch Exchange). These systems have circuitry for summing and balancing the energy (noise) on each channel so everyone can hear each other. More sophisticated conference bridges have the ability to "idle" the transmit side of channels of non-speaking parties. Some conference bridges use "clVoxising" to idle or reject the input of touch tones or other signals.
