As I was saying, I sometimes wake up before the alarm, usually because of some noise outside the house—a car door slamming, an alarm going off, gunfire—well, okay, not gunfire, but man, is my neighborhood noisy!

查原文，is my neighborhood noisy：is 还是 in？

some noise 是because of 的宾语，不可能是主语。破折号中间的部分是对 some noise 的说明，是同位语。