As someone who hears on average, less than 30% of the sounds one normally hears in their day, I am often startled by hearing something I didn't think I'd be able to. Which makes me look like a weirdo to onlookers who either do not know I'm deaf to begin with, or for some reason believe that hearing aids cure deafness. They do in fact not cure deafness. I'm not sure why people seem to think they do, but they do not. Just had to take a moment of time to clear that up for everyone.
My hearing aid improves my environmental awareness, certainly, and I hear a lot more than I otherwise would without it, but I still do not hear everything. Without my hearing aid I'd say I can faintly hear about 5% of the sounds one normally hears in their day. With it I hear about +25% more sounds, granted some of them are still indecipherable. It more or less gives me a greater sense of where a sound may be coming from. Making it less likely I will get hit by a car... or a train.
So when I am walking along and suddenly an eagle cries out from above me (something you don't hear often to begin with), I may jump -- startled. Not because I have a strange fear of eagles but because I had not anticipated the sound. Even if I see something I know will make a sound should I step on it (crunchy leaf), or bump into it (tall hedges), or even simply pass it by (unruly dog), I'm still startled when it makes a sound and I hear it. Because I am used to the world being a very quiet place.
So this morning, when I bumped a paper bag which had fallen under my desk with my foot and it made a sound, I recoiled in fear. Not because paper bags are terrifying but because first of all, I didn't even know it was down there and second of all I rarely ever hear paper make a sound anymore. Which had to look funny and/or retarded because Aaron was like, "What the hell?" and giving me a weird look. Then I had to explain to him what had happened and why it had happened, even though I'm pretty sure he understands, just to placate my own mind about why I overreacted to a paper bag.
This gave me the idea to just explain it to everyone simultaneously, so that I do not feel obligated to explain it to you when it undoubtedly happens again at some point in your presence. I am not scared of mundane objects. I promise!