1.   But for him, the train whistles would always have a North-bound sound.

2.   Each whistle had a different sound, he recalled, and some people could pick out which factory was calling.

3.   The train whistle still has a North-bound sound.

4.   Two apparent Hartford goals were disallowed, one because the puck was kicked into the net, the other because a whistle had blown.

5.   When the train is moving away, the whistle has a lower pitch.

6.   Whistle had its own reasons to become part of IBM.