Listen: sounds near 21 dB
How loud is 21 dB?
21 decibels is very quiet. 21 dB sounds about 14.9 times quieter than normal conversation (60 dB), and it carries 0.000126 times the sound energy. Typical sounds around this level: normal breathing, rustling leaves, ticking watch.
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 21 dB safe?
Yes. 21 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 21 dB
Measured close to the face in a very quiet room.20 dBRustling leaves
A gentle breeze moving through foliage.20 dBTicking watch
Held about arm's length away.25 dBCat purring
Purrs are low (25–150 Hz) and quiet; most are about 25 dB at a short distance.30 dBWhisper
A soft whisper at about 1.5 m (5 ft).
Frequently asked questions
Is 21 dB loud?
21 dB is very quiet. For comparison: normal breathing, rustling leaves, ticking watch.
How many times louder is 21 dB than 11 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 21 dB?
21 dB is safe for unlimited listening.