I am researching the history of church bells and of bell ringing. When were church bells used for the first time and why were bells used instead of the human voice to call people to prayer?
Answer: Information on bells as a church instrument and references to further literature can be found in many good encyclopedias and dictionaries. See for example the entry for bells in “The Oxford Dictionary of the Christian Church”. Oxford: Oxford University Press, 1974, p. 153.
Here only a few key data: The bell (Irish "clog; old German "clochon – knocking, giving rise to the German word "Glocke") is an instrument that was already known in ancient China. Its use in churches is mentioned as early as 400 by Paul of Nola. Bells are introduced in France around 550 and in the 7th century in Ireland. The ringing of the bells calls the people to the church services. In former times, the bell was not only used to announce Holy Mass, but also rang three times a day (early in the morning, at midday and in the evening) to call people to the Angelus prayer.
As the bells increased in size, special towers to hang them in became necessary, either a free standing bell tower, or one integrated in the church building. The bell-foundries, initially operated by the monks, were transferred in the 13th century to the professional founders. The secrets of bell-foundry were passed down the families.
In Germany, bells are consecrated by bishops or authorized priests. While prayers are being said the bell is washed with holy water (this is also called the baptism of bells), anointed with consecrated oil and blessed. The bell sponsor gives it a name. The bells can be the property of the church, of the parish or in private use. Only the clerical authority has the right to determine the use of a bell. If it is to be used for civil occasions, a relevant license is necessary (ceremonies and public announcements).