re: cazaly--freo?. From Laws of Australian Football 2004:
10.4.1 End of Quarter
The Timekeepers shall sound the siren to signal the end of a quarter until a field Umpire acknowledges that the siren has been heard and brings play to an end.
10.4.2 Siren Heard by Field Umpire
Play in each quarter shall come to an end when any one of the field Umpires hears the siren.
