[list=1]
[li]Who–invented the fire/police siren?[/li][li]Where–was it first used?[/li][li]Hi Opal![/li][li]When–was it first used?[/li][li]Why–sirens, & not bells or other noisemakers?[/li][li]Does–Opal sound like a siren? Greek or air raid? If the latter, what is her connection to Selene Dion? And, what about Naomi?[/li][/list=1]
Googling around a bit, the siren was apparently invented by a German guy named Louis Seebeck (1805-1849). That’s all I can find for the moment.
Thanks to pravnik’s tip, I found this page on early sirens. Seems to have initially been “a device for determining the absolute frequency of a sound”, according to that page. A. Seebeck is listed as one of the designers.
I’d say, as a WAG, that sirens developed into being a warning signal with lighthouses.
Why sirens and not bells? Bells were used for 19th century fire-fighting wagons, but sirens carry sound better and at greater ranges, I guess.