Well, I don't usually get startled too easily unless I hear something sharp, sudden, and loud. I usually just tell people I have sensitive hearing, which I do, but that doesn't mean that loud noises bother me :P

For me, it totally depends on my mood. For example, sometimes I go through phases where I like to scare myself by reading spooky stories online. If that is the case, I get startled very easily. Yesterday I was in my room, and my boyfriend opened my door. He didn't make any noise or anything, but that door opening made me scream and jump, because I had just got finished reading a creepy story.

Usually though, I'm not scared easily. People jumping out at me or trying to scare me generally doesn't phase me, or anything like that.

I get startled when I watch others play horror themed video games on Youtube, I enjoy most parts of those videos but if it gets too creepy I look away from the computer screen and cover my ears. But despite that I can still hear the person playing it scream which makes me scream as well.

Im easily startled. If i dont hear someone coming up behind me (btw, i have terrible hearing, so this doesnt work out so well xD) and they touch my shoulder or something, i'll jump. I let my imagination get the best of me. All of the time. I cant stand to be the only one awake at night, because even then a toilet seems to be a monster O_o

I basically have a heart attack whenever something moves.