11.   Five minutes later, the sound of the jets suddenly became clearer, and the shrill whistle of a bomb hurtling through the air grew louder and louder.

12.   Just then, a shrill whistle blasted the air, followed by loud, unseemly grunts.

13.   Last year may have been a Super Bowl season, but practice is still one shrill whistle after another.

14.   The first shrill whistle, like an arrow stuck in his ear, assailed Pete Sampras as he knocked a routine forehand well out of the court.

15.   We watched strange round test patterns on the black-and-white TV that blared a shrill whistle for a minute.

16.   The air vibrated with shrill whistles, and an occasional firecracker popped among the marchers.