she was so loud, her mouth (literally) had to be kept shut
... someone had to cover her mouth
... someone had to shut her mouth (for her)

e.g.

bzw.: Ich bekommen immer den Mund zugehalten..

ach dude..wenn ich dich nicht hätte

"

@stu22: just to shut her up, all you'd have to do is point a gun at her, for instance, or knock her out cold. :-)

@shutterupper
she might still snore, though

the only way to be really sure is to move to Germany without leaving a forwarding address

Was heißt denn dann er hielt ihr den mund zu?

Danke für alle Antworten!