Diaphone

A Type B Diaphone (Gamewell) in front of a Type F Diaphone fog horn (Diaphone Signal Co.) previously used in Cleveland, OH.

The diaphone is a noisemaking device best known for its use as a foghorn: It can produce deep, powerful tones, able to carry a long distance. Although they have fallen out of favor, diaphones were also used at some fire stations and in other situations where a loud, audible signal was required.

Sound of the diaphone at East Brother Island Light, a lighthouse located at Richmond, California.