The Close Before You Doze Series: Decibel Readings
Craig Weinschenk
December 8, 2017

As part of the Close Before You Doze full-scale experiment on October 10, 2017, Steve Kerber, the Director of the UL Firefighter Safety Research Institute, took measurements 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. The data is shown in Table 1. Here is how these tests were conducted:

Table 1: Average Decibel Measurements

Status Decibels (dBA)
No Alarm 35
Alarm with Door Open 95
Alarm with Door Closed 78
UL Firefighter Safety Research Institute is dedicated to increasing firefighter knowledge to reduce injuries and deaths in the fire service and in the communities they serve.