Spreading the Word that Stops the Spread of Fire: Close Before You Doze

Decibel Ratings Taken to Understand the Difference Between the Loudness of Smoke Alarm Outside of an Open or Closed Door

Fire Safety
December 31, 2019

decibel meter placed on a bed

As part of the Close Before You Doze full-scale experiments conducted in October, Steve Kerber, the Director of the UL Firefighter Safety Research Institute (FSRI), took measurements using a decibel meter in a bedroom with a sound level meter and recorded the difference between the loudness of a smoke alarm with the door open and the door closed. This portion of the experiment was conducted to help dispel the myth that a smoke alarm can not be heard at a reasonable level with the door closed - a common reason why people say they do not close their bedroom door before going to bed. 

The data is shown in Table 1. 

table showing measurements from a decible meter

Watch this video to see how the experiments were conducted:


Open vs. Closed Door Decibels from the UL Firefighter Safety Research Institute (UL FSRI) on Vimeo.

Relevant Resources:

RESOURCE #1: Closeyourdoor.org 

RESOURCE #2: Myth Extinguisher Video: I won't be able to hear my smoke alarm with my door closed.