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Decibel chart › 40 dB
How loud is 40 decibels?
40 decibels is about as loud as a refrigerator hum. It is well under the 85 dB hearing-risk line, so it carries no hearing-damage risk at any length of exposure. Sleep is a separate question: the WHO night guideline is 45 dB. On the decibel scale, each 10 dB step sounds roughly twice as loud. Measure it yourself with Decibel Shield's free online decibel meter.
Last updated:
| Sound level | 40 dB |
|---|---|
| Hearing risk | No hearing risk |
| Safe exposure (NIOSH) | No limit — safe at any duration |
Measure 40 dB yourself
Want to know if where you are hits 40 dB? Press Start and the meter below reads it live. It runs in your browser, and nothing is recorded or uploaded.
What is comparable to 40 decibels?
Everyday examples of sounds around 40 decibels, each sourced to CDC, NIOSH, NIDCD and ASHA. Open any one for its own breakdown, or see the full decibel levels chart.
- Refrigerator hum 40–45 dB
Is any city as quiet as 40 dB?
No mapped city averages 40 dB outdoors. The quietest cities in the official noise maps sit around 45–60 dB by day. These are the quietest mapped.
- Lehigh Acres, FL only 0.5% of residents at 60 dBA or more
- Torrejon de Ardoz 45–60 dB by day
- Newport 55–65 dB by day
What does 40 decibels sound like?
40 decibels is about as loud as a refrigerator hum. It is well under the 85 dB hearing-risk line, so it carries no hearing-damage risk at any length of exposure. Sleep is a separate question: the WHO night guideline is 45 dB. On the decibel scale, each 10 dB step sounds roughly twice as loud. Measure it yourself with Decibel Shield's free online decibel meter.
Is 40 decibels too loud?
40 decibels is moderate, about the loudness of a refrigerator hum, not what most people would call loud. It sits around everyday conversation and background sound, and is comfortable to hear for any length of time.
How long is 40 decibels safe to hear?
40 dB is below the 85 dB hearing-risk threshold, so there is no daily exposure limit for hearing.
How far away can you hear 40 dB?
In open air a small source measured at 40 dB from 1 m falls to about 20 dB at 10 m and 0 dB at 100 m, losing 6 dB each time the distance doubles. You keep hearing it while it stays above the background level around you: farther in a quiet field at night, much less on a 60 dB street. Walls, ground and wind change the figure.
Work out any distance, or a line source such as a road, with the sound distance calculator.