Listen: sounds near 40 dB
How loud is 40 dB?
40 decibels is quiet. 40 dB sounds about 4.0 times quieter than normal conversation (60 dB), and it carries 0.01 times the sound energy. Typical sounds around this level: whisper, quiet library, refrigerator hum.
Decibels are logarithmic: every +10 dB means ten times more sound intensity but is heard as only about twice as loud, and every +6 dB doubles the sound pressure. That is why a few decibels can make a big difference.
Is 40 dB safe?
Yes. 40 dB is far below the levels that damage hearing. In bedrooms, the WHO recommends night-time levels around 30 dB or lower for undisturbed sleep.
Sounds around 40 dB
A soft whisper at about 1.5 m (5 ft).40 dBQuiet library
Background level of a quiet reading room.40 dBRefrigerator hum
Modern fridges are often rated 32–40 dB.50 dBModerate rainfall
Steady rain heard from outdoors under a roof.50 dBQuiet office
Typical open office with low conversation.50 dBTyping on a keyboard
Mechanical keyboards are louder than laptop keyboards.
Frequently asked questions
Is 40 dB loud?
40 dB is quiet. For comparison: whisper, quiet library, refrigerator hum.
How many times louder is 40 dB than 30 dB?
A 10 dB increase means ten times the sound intensity and is heard as roughly twice as loud.
How long can you listen to 40 dB?
40 dB is safe for unlimited listening.