It hummed gently with the heat from the blazing logs.

At his side a radio hummed gently to itself.

At that point, Duncan's badge started to hum gently.

The temperature was cooler in here; I could hear the air conditioning humming gently above me.

Behind me, the plant hummed gently, its skylights glowing in the night.

There was no one in the first room, where the server's cooling fans were humming gently.

She then stepped a few paces aside and put her face close to the dial of a gently humming machine.

With the flip of a switch, it hummed gently into active mode.

Then, humming gently, the door opened and Marten stepped in, shutting it behind him.

The tall cabinet full of valves began to hum gently.