It is a unit of sound measurement, for its intensity or its relation to voltage in amplified sounds. It is not absolute and you work with a reference value ( p . e.g. the threshold of human hearing). Its symbol is B ("bel o belio"). The name is a tribute to the engineer Alexander Graham Bell, who drove the development of telephony in the nineteenth century and proclaimed himself the inventor of the telephone, although the true creator of the technology was the Italian Antonio Meucci. See decibel.
