... or Martin-Trumpet
In any other context, the “Schalmei” (French chalumai, English shawm) is a completely different instrument: a woodwind forerunner of the modern oboe tracing back to the Middle Ages (see the sidebar) . How the name came to be applied to two such unrelated instruments is not clear, but this otherworldly German cousin to the military bugle is also called a Martin’s Trumpet (named for the inventor Max Martin
Shawm: the Predecessors
Shawm are double-reed woodwind instruments made in Europe from the 12th century to the present day. Their classic Renaissance sound was gradually eclipsed by the oboe family of descendant instruments in classical music.
More on Max B. Martin
In the early days, motor car horns and fire horns were production-priorities. These were also the years when many volunteer fire brigades called Martin Chapels were already responding to fires using onboard 8-tone Martin trumpets,
In 1932 they developed the German signal instrument factory to manufacture for fire and police departments a horn with a "prescribed priority warning". Up to World War II, these horns were made for emergency vehicles only.