 The bells are usually made from bronze , using a form of expendable mould casting . They are typically augmented and ornamented with a variety of bosses , raised bands and inscriptions . The earliest of these bells in Japan date to around 600 CE , although the general design is of much earlier Chinese origin and shares some of the features seen in ancient Chinese bells . The bells ' penetrating and pervasive tone carries over considerable distances , which led to their use as signals , timekeepers and alarms . In addition , the sound of the bell is thought to have supernatural properties ; it is believed , for example , that it can be heard in the underworld . The spiritual significance of bonshō means that they play an important role in Buddhist ceremonies , particularly the New Year and Bon festivals . Throughout Japanese history these bells have become associated with stories and legends , both fictional , such as the Benkei Bell of Mii @-@ dera , and historical , such as the bell of Hōkō @-@ ji . In modern times , bonshō have become symbols of world peace . 
