Seeing that It's much bigger than a regular hand held whistle that we can find in the twenty first century, I knew people didn't carry these around. This was more horn like item, that was stationed on large castles. The sound on it projected miles, which doesn't surprise me much because of its absurd size. As soon as a watchman saw an oncoming intruder he would run to the whistle to sound the men. During this time they were facing wars from many groups including, Persia, Avars, and Muslims. These times of war made the Byzantines quite clever. With the help of these whistles the, Byzantine emperor, Heraclius regained all of the land they've lost in previous wars. The crafty and war efficient whistles showed the keenness of the Byzantine empire. One simple blow and every soldier would be to their post ready for battle.
The large headlike whistle, that i found so infatuating was so efficient to the Byzantium's that they eventually made smaller whistles that they could take into battle. Some people even used the smaller whistles for when they were coming back from secret missions to inform the people that it was them and not some