How To SURVIVE A Quiet Place! | Film Theory

Summary by Krater

This video calculates the decibel levels and resonant frequencies required to trigger the death angels in A Quiet Place, concluding that the monsters respond to sounds above 50 decibels between 1400 and 1900 Hz.

From the video

Answers: How loud can you be in A Quiet Place before the monsters hear you?

• A Quiet Place sound physics
• Monster hearing sensitivity analysis
• Decibel attenuation calculator
• Resonant frequency of alien armor
• Temperature inversion sound propagation

What it concludes

• Toy rocket ship noise blasts off at 105 decibels, which can be easily heard by the aliens.
• Walking on dried leaves clocks in at a minimum of 55 decibels, while stepping on a stick reaches 70 decibels.
• Normal conversation in the 60 decibel range can be softened down to a whisper at around 30 decibels to stay safe.
• Temperature inversions at night cause sound waves to refract back down towards earth, allowing sounds to be heard over longer distances.
• The death angels' weakness is tied to a resonant frequency between 1400 and 1900 Hz.