Googley- I understand the startle repsone. Remember too that screaming is a good self protective skill. Maybe you could see it as a way to take care of you?

About 15 years ago I took a self defense class where we practiced yelling at attackers- and I excelled. We'd ye;; "get the F--- away from me!" very powerful.
I did learn that response very well- not always so good when in bed with a partner or a child comes creeping down the stairs! lol My family has learned to announce themselves and I of course have done some apologising... but I know that my voice can help keep me safe.