We would be outside the outer glass box and talk to him via an intercom system.
The school had an intercom system aimed at stopping unauthorized entry--and he did it anyway.
“This one is for you, Salman,” George boomed over the intercom.
I was sitting in a 6th grade classroom when the principal came on the intercom to say the president had been shot.
As Thane lined up the pirate again, the intercom said, "Five seconds to warp-line!"
He picked up the first card, and dialed the man's intercom number.
He clicked off the teleceiver and turned back to the intercom.
In one quick movement, he spun his chair around and jabbed at the intercom.
The intercom buzzed again, and Gelsen irritably punched a button.
Bending over his desk, he nudged an intercom button with his finger.
An intercommunication system: Marc yelled into the intercom (1940s+)