Background on Emergency Sirens

Over the next three days, JP Patch presents a series of quizzes about Boston sirens. .

And here's some background on sirens:

Of the five human senses, hearing alerts the brain to danger most quickly.   "Hearing is considered to be a primary warning sense," according to the National Academies of Emergency Dispatch. "A loud auditory signal may exert an immediate arousing effect."  For this reason, emergency vehicles, fire engines, ambulances, and police cars, sound high decibel sirens to alert motorists and pedestrians to move out of the way. 

When the sounds of the day have quieted and buses and trains have ceased to run, sirens disrupt the stillness, drawing much more notice than during the day. 

Until recently, all forms of emergency vehicles used the Q2B siren.  Now, only fire engines carry the Q2B siren, which wails and yelps at 123 decibles. Police cars and ambulances typically use electric sirens.

If you are upset about the loudness of sirens as they pass by your street, one of the best ways to get involved is to contact the District 13 Police Station. Sirens are a subject often discussed in the Strategic Action Planning Team that deals with noise and graffiti.

[Editor's note: The original post of this story gave incorrect information about who to contact for the Strategic Action Planning Team.]