Then they began to hear a dull roar from somewhere in front of them.

In the street behind him, a dull roar exploded into thunder.

He could hear the traffic in the street, the dull roar of white noise.

I'd like to keep the scandal down to a dull roar.

AT that moment a dull roar sounded from far above.

Listening, he heard only the dull roar of the river.

Tell everybody to keep it down to a dull roar, won't you?

He became aware of a dull roar in his ears.

While on the street, he heard a dull roar and knew instantly that something was wrong.

"They keep the crowds down to a dull roar by letting everyone in for only a few hours a day."