Definition of diaphone in US English:



  • A low-pitched fog signal operated by compressed air, characterized by the “grunt” that ends each note.

    • ‘The diaphones were absolutely deafening and sounded a 2 tone blast every minute or less.’
    • ‘The Oral History Division of Simon Fraser University did what they called a ‘Vancouver Soundscape’; its highlight was the diaphone foghorn.’
    • ‘Below are pictures of the diaphones at each firehouse.’
    • ‘In later years the oscillator was replaced by a duplicate diaphone to be used in the event of breakdown.’
    • ‘The diaphone has been likened in some descriptions to a reciprocating siren, which in fact it is.’
    • ‘To anyone in our hobby, however, the sound of the diaphone is magnificent.’
    • ‘A radio beacon as installed in 1927 and five years later the diaphone and radio beacon were synchronized to help guide them safely into the harbor.’
    • ‘I spent a night and day within a few feet of one of the most powerful lighthouse diaphones on the coast.’
    • ‘Use of the diaphones was limited after some lawsuits were filed against the Borough by nearby residents.’
    • ‘A honeybee hive occasionally inhabits the top of the tower right next to the diaphone itself.’
    • ‘In 1991 the diaphone fog signal was changed to an electric horn retaining the same character.’
    • ‘Fog signals have included cannons, whistles, sirens, reed trumpets, bells, diaphones, and diaphragm horns.’


Early 20th century: from Greek dia ‘through’ + phōnē ‘sound’.