It definitely can get better.
I noticed a particular one the other day, in fact ... my husband tends to hit the doorknob fairly hard when he comes out of the room - and the clatter used to send me absolutely through the ceiling! Heart racing, the big jump, everything.
He did it the other day and I just went "argh I wish he could do that a little more quietly". No jump. No startle. Just a minor annoyance.
There's hope!
Also, there's Prazosin. :) I take it at night to help me sleep but also in the day to help keep me a little less tightly wound. It's made a big difference.