It's so easy to tune out everyday sounds that I do it in writing too, and never mention the noises around my hero...until he hears the ominous sching of a sword being drawn or the snap of a twig in a quiet forest. :)
1) For me, the biggest noise I hear is the traffic. We live not far from Marquette's main drag and it can be loud. For Varian...probably people talking, seeing as how he lives in a castle.
2) Computers. I spend most of my day around computers humming, beeping and making other annoying sounds. Varian's second would be animals, again since he lives in a castle that has pretty large stables.
3) Music. As I'm writing, I listen to soundtracks. I hear it on the TV shows my husband watches and the video games he (and yes, I) play. Varian's third most common sound would probably be the sound of wood crackling in the fireplace, since the world he lives in (Absor) is medieval and fire is their main heat source.
I don't know about you guys, but this was hard! I didn't pause for a moment when I thought about the sounds I hear everyday, but when I had to step into my character's shoes, it got tough. But when I'm reading a novel, descriptions of sounds make it come alive, so I know it's essential for my novel to have noises.
What 3 noises do you (or your main characters) hear every day?