Everyone living in a city tunes out city noise. Constant sounds like cars driving by are easy to tune out completely. Less frequent sounds, like a helicopter flying overhead or an ambulance rushing by, are hard to tune out completely but easy to ignore.
Emergency sirens are a great example. I certainly hear them, but unless they’re going right past my building I just ignore them and continue focusing on what I was doing.
Tonight, I was watching a movie in which a character says:
I can’t think with all these sirens!
And all I could think was: “What sirens?”
I had to pause the movie to realize the sirens I was hearing and ignoring were actually an important part of the plot I was supposed to be enjoying.
Blërg.