The buzzer on the intercom unit to one side of the table interrupted her thoughts.

Monitor - Usually this means the ability to listen to what is happening at a wireless intercom unit.

Conference - The ability to talk to multiple intercom units at once.

The intercom unit on the table came to life.

Heading for the doctor's intercom unit, he laid his hand over the metal strip.

Bell was still standing at the intercom unit, giving his call.

Some ten minutes later, the intercom unit by Tad's bed buzzed.

He spoke into the intercom unit on his chair.

He touched the intercom unit that sat on the bureau.

An intercom unit was located a few meters down the corridor.