Sara, et. al,

The rule prohibiting artificial noisemakers whether used or not is in
the NCAA General Championship Information packet.  The items in this
packet are strictly enforced at all NCAA run events (ie the regionals
and FF).  Many leagues also use these rules as the base point for their
individual playoffs.  Most leagues do not enforce them during the
regular season games, only during playoffs in order to make the various
host rinks more "neutral".

The rule is:
"Artifical Noisemakers:  Artificial noisemakers, air horns and
electronic amplifiers shall not be permitted, and such instruments shall
be removed from the playing and spectator areas.  Bands, or any
component thereof, shall not play while the game is in progress.  The
tournament manager shall be responsible for enforcing these provisions."

Scott