It's interesting. Because she has no vocal cords, she can't release her fear tensions vocally as we can, so they continue to mount, until she can't endure it.
12 seconds sound clip from the The Tingler (1959) movie soundboard.
You can hear this line at 00:12:06 in the Blu-ray version of the movie.
Quote context
[...]
- No, it's nothing but a small cut.
- Go down and get the bag out of my car.
- She always does this. One drop of blood and out she goes.
- Well, it affects some people like that.
- Did you notice how rigid she became just before she fainted?
- It isn't a faint as we know it. It's more of a psychosomatic escape.
- You go downstairs and open up. I'll come downstairs in a minute.
- It's time to open up the box office.
[...]