The sound of approaching sirens came, muffled, through the walls.

Coupled to that, they heard the whine of approaching sirens.

The Shadow didn't flee at the sound of those approaching sirens.

He heard the wails of approaching sirens and knew why the police were coming.

The sound of approaching sirens meant other units were on the scene, responding to my 10-1 call.

He paused as his ears caught the distant sound of approaching sirens.

And then he heard it- the sound of approaching sirens.

From outside he heard the shrill sound of approaching sirens.

Now all the windows were breaking, and somewhere close by Pearson could hear approaching sirens.

Off in the distance, they heard the sound of approaching sirens.