If one did not count the low hum of conversation here and there.

On a low hum of pleasure her head fell back.

From deep within the heart of the giant ship, a low hum began.

The low hum of the force field had gone, he noted.

She heard the low hum of a computer coming from inside.

For a moment, the only sound in the kitchen was the low hum of the refrigerator.

The low hum that had been coming from it stopped.

There seemed to be a low, electrical hum coming from all over his body.

She could hear a low hum of voices, and wanted nothing more than to run away.

Sister heard the low hum of another fly as it passed her head.