Facts about Noise, Sound, Decibels, and Hearing
Terms, statistics, and facts about noise and noise levels.
Noise Levels and Hearing Damage
If you remember nothing else from this website, remember this:
Eighty-five decibels (dB) is the level above which
is recommended, to avoid hearing loss from the cumulative effects of exposure to noise over time. How can you tell if the noise level is 85 dB? Here's a quick test: If you have to raise your voice to talk to someone who is an arm's length away from you, you are likely in an environment with a sound level of 85 dB or more.
The higher the noise level, the less time it takes for damage to occur.
This chart of noise exposure levels
shows the maximum safe time limits.
Measuring Noise and Hearing
As you probably know, noise levels are commonly measured in decibels (dB). It is a logarithmic scale rather than a linear one, because the human ear can handle such a vast range of sound levels. Zero dB is the softest sound a healthy human ear can detect.
Read more about the decibel scale and other sound measurement units.
this noise level chart
for decibel levels of common sounds.
Instruments for measuring noise levels and hearing include:
- Sound level meter, or decibel meter: Used to take a reading of the noise level at any given moment.
- Noise dosimeter: Used to measure the average noise exposure during a given period of time, such as an eight-hour workday. This helps determine whether the cumulative amount of noise that a person is exposed to is hazardous.
- Audiometer: Used to test a person's hearing, to identify and quantify any hearing loss. It can be a precision instrument, as used in clinics and occupational settings, or a home audiometer device or PC software program for basic screening. Results of audiometric testing are plotted on a chart called an
- 39% of US adults have had their hearing tested within the last three years.
- 21% of US adults over age 65 say they have never had a hearing test.
For adults with healthy hearing and no hazardous noise exposure, a
is recommended every three years. For those who are exposed to
hazardous noise levels,
annual testing is recommended.
Learn about different types of online hearing test,
take a hearing screening questionnaire.
Facts about Noise-Induced Hearing Loss
- At least 15% of adults have permanent hearing damage due to noise exposure.
- In 2005-2006, 20% of US adolescents 12 to 19 years old had some degree of hearing loss. This is up from 15% as measured in 1988-1994.
The World Health Organization (WHO) reports that the single most common irreversible occupational hazard worldwide is noise-induced hearing impairment.
FAQ (Frequently Asked Questions) about noise and noise pollution
Noise pollution laws
Some practical ways for dealing with noise problems
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