1.   Sammy put his finger and thumb in his mouth and gave a piercing whistle.

2.   Sammy put his fingers in his mouth and gave a piercing whistle.

3.   Suddenly I heard a piercing whistle that seemed to resound through the whole universe.

4.   Suddenly I heard a piercing whistle.

5.   He grinned and let out a piercing whistle.

6.   ...a piercing whistle.

7.   There was a piercing whistle and a little boy ran across the rubble towards them.

8.   Suddenly there is a piercing whistle from a limo radio.

9.   The piercing whistles that greeted every American surname when the lineups were announced.

10.   Memories of the days when trains belched smoke and emitted piercing whistles send buffs searching the globe for a ride behind a vintage engine.