The constant hum of voices through the door was company enough.

The constant hum of criticism has clearly got to Tarses.

Throughout the gulf region these days, there is a constant hum of military preparations.

There was a constant hum of chatter, and the occasional laugh.

A constant, low hum of power was audible from inside it.

Only the constant hum of the machinery below broke the quiet.

The air was filled with a constant hum and vibration.

Only the constant hum of the radar beam linked them with reality.

The constant hum of the insects suddenly hushed off to our left.

His work also brings to mind the constant hum of machines and electronics in modern life.