Except Dinah couldn't hear anyone talking in the big airplane's main cabin; only the steady soft drone of the jet engines.

Only the steady soft drone of the jet engines.

Downstairs, he heard the click of dishes and soft drone of the news.

Spock's voice began a soft drone of lower deck reports.

The soft drone of the buffer made him feel sleepy.

Behind him, the soft drone of the floor-buffer recommenced.

It was quiet, except for the soft drone of cicadas.

The sound of the motors was a soft drone.

The usual sputtering began, turned to a whine, and terminated in a drone so soft as to suggest a return to silence.

Wisar squatted beside him, his voice a soft drone.