By now, of course, Graydon had realized that the unseen speaker was not really in the rock chamber, but behind the wall.

The unseen speaker had nothing of censure in her voice; she sounded excited.

A female voice came over the booth's unseen speaker.

I stamped and coughed and moved closer to the unseen speaker.

He and Gavlok were now on their feet, looking this way and that for the unseen speaker.

"I certainly can," the boy said, stopping and looking around for the unseen speaker.

The voice of Omnius blared from unseen speakers all around him and throughout the city.

How soon before an investigation would be launched by the unseen speaker?

"Our manager is on his way," Kirk told the unseen speaker somewhere out there in the rain and darkness.

A voice came from an unseen speaker in the wall, not his combadge.