The earliest archeological evidence of bells dates from the 3d millennium BC. You can trace it back to the Yangshao culture of Neolithic China. Bells first started as clapper-made bells of pottery. Then, they develop into metal bells.
Bells have a deep symbolic meaning associated with the mind and the expansion of consciousness. They are also associated with clocks, indicating the hour by ringing.
In most cases, bells symbolic beginnings and endings. You can hear bells ringing at weddings, funerals, but also at sports events.
In Christianity, bells appeared in churches around 400AD and by about 600AD they become common in monasteries.