I don't know that specific area, but...
I grew up about half a mile from some major railroad tracks (main line of Southern Railway outside of Washington, D.C.). The train went right through a small nearby town. What I found is that most people get used to it. Really. Even though the horn (as noted already) is generally the loudest element. Approaching an intersection: LONG-LONG-SHORT-LONG.
Further, sound carries farther in colder weather. It also carries farther when the leaves have fallen. I don't know if you get that in Mountain View--seasons, leaves falling, etc. But if you do, it'll sound louder then. It also carries farther if there aren't any intervening hills, which can muffle the sound.
As for going out there and listening to the train: Certainly do that. But, honestly, it'll sound pretty loud. Getting adjusted to the sound Is about 70% of the solution. It's also possible to largely soundproof your home. That's done more often near airports and airplane flight paths. It's pretty effective, but can be expensive. And while it'll cut down on the sound, it won't cut down on the vibrations.
Better than just listening to it: Go out there and ask other people who live there whether the noise bothers them. My guess is: Probably not. But that's something you definitely should do.
One other point: The rumbling generally isn't the problem. Nor, after you get used to it, is the train horn. But what can be irritating is if you're near a switching yard. In that case, you might get a lot of high-pitched squealing and squeaking. That often is the big problem.
Hope that helps.