Which unit is used to measure sound intensity?

Player Say what!?, The diving bell predates Alexander Graham Bell by centuries. It gets its name from its shape.

Actually a Decibel (dB) is a relative scale to measure a number of engineering parameters. The unit of sound intensity is the dBA. Where A stands for acoustic.

So called because Alexander Graham Bell created the way to measure sound-he dropped the second "l". Besides that and the telephone, he also invented the Diving Bell.