For us Larkspur folk, the high point of the film is undoubtedly the fire call sequence. The actual sound of the fire horn (or whistle, as we always called it in our family) was recorded, and the sequence then begins with a shot of it on the City Hall tower.
To hear the Larkspur horn, a Diaphone, click here (27K mp3 opens in new window).
Another Diaphone fire horn can be heard the 1956 science-fiction film Invasion of the Body Snatchers.