The koan:

If Non-Sensei speaks but NOBODY listens, was anything actually said?

The end of a fairly large childrens class, moments after the class had been dismissed one of the instructors yelled "P-R-A-C-T-I-C-E" fairly loudly.... the same word used as far back as could be remembered.

Class was over... they were released and scrambling into their parents arms, their coats, boots, etc... one of the parents a good, honest man amused that none appeared to hear was compelled to ask the "koan" above...

My answer was laughter. What is your answer to this ~koan~...? If they do not hear the words, were they spoken?