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.