 The sonorous sound of the bell was also used to warn of impending typhoons and as a general alert . Because the ringing of a temple bell could be heard over considerable distances , it was also sometimes used for other signalling purposes ; there are records of temple bells being used for military communication from as far back as the Genpei War ( 1180 – 1185 CE ) . Smaller versions were subsequently cast for battlefield use , as the large temple bells were too heavy and unwieldy to transport . These smaller bonshō were used primarily as alarms to warn of enemy attacks ; commands were given using drums and conches . 
