Other mistake: The construction of a staircase does not require a large nail at the site shown on the steps. Furthermore when Emily snags her clothes basket on the stairs it lifts a small nail up. How did it grow into a 2 inch fat nail?
A Quiet Place (2018)
1 other mistake - chronological order
Directed by: John Krasinski
Starring: Emily Blunt, John Krasinski, Noah Jupe, Millicent Simmonds
Factual error: Emily Blunt takes her blood pressure manually, pumping up a cuff but not listening to her pulse with a stethoscope to get the reading. Not possible without a new style automatic BP machine which would have made noise.
Marcus Abbott: You still love her, right?
Lee Abbott: Of course I do.
Marcus Abbott: You should tell her.
Trivia: Test screenings for this were next to impossible - John Krasinski played the monster in a motion capture suit, but the CGI wasn't completed so audiences kept laughing at him whenever he came on screen instead of being scared by the monster.
Question: If the waterfall prevents the creatures hearing them, why not live there?
Suggested correction: This is simply not true. The style of BP monitor that she uses is the way all BP monitors used to work.
The way you use a manual BP cuff is by listening to your pulse with a stethoscope while you pressurize the cuff. Your top number is the pressure you hear your pulse stop, and the bottom number is the pressure where you hear it pick up again.
Suggested correction: It is possible to read the pressure by such a machine as shown in the movie after some practice. The needle or the indicating hand slightly skips when it reaches the read pressure range.
That's inaccurate. The pressure at which the gauge jumps is often different than the pressure at which the first Korsakoff sound is heard.
Suggested correction: You can watch the needle bounce with the pulse on any sphygmomanometer - not as accurate as with a stethoscope but would work just fine.