A device used in audio conferencing that connects multiple telephone lines.

A device used to conference, or "patch", multiple audio telephone calls together to enable all parties to simultaneous participate in the audio conference.

Equipment that mixes multiple audio inputs and feeds back composite audio to each station after removing the individual station's input. This equipment may also be called a mix-minus audio system.

A device used in audioconferencing that connects multiple telephone lines. Audioconferencing: Voice only connection of more than two sites using standard telephone lines.

Specialized equipment that interconnects three or more telephone lines (usually operator assisted) to enable conference calls. The audioconferencing equipment needed to connect multiple sites can be provided by companies specializing in bridge services.

A method used to connect multiple telephone lines for an audioconference.