Interactive US Maps of Noise Exposure

An Update from the Apple Hearing Study on International Noise Awareness Day 2023

by the Apple Hearing Study team and graphics by Abas Shkembi

Last updated April 26, 2023

Noise pollution – that is, unwanted, distracting, or harmful sound – affects all of us. We are surrounded by noise from cars, airplanes, workplaces, and leisure activities such as concerts every day, and our personal experience of noise can vary.

The World Health Organization (WHO)1 and the US Environmental Protection Agency (EPA)2 have identified an annual average noise exposure level of 70 decibels (dBA) as the level below which there is no risk for hearing loss.

For the purposes of the Apple Hearing Study, we assume that people who repeatedly experience daily average noise exposures over 70 dBA likely have an annual average noise exposure over 70 dBA.

These exposures may damage your hearing, cause annoyance, impact your heart, disturb your sleep, and impact mental health3. Longer exposures, and exposures at higher levels, increase the risk of these impacts.

While in use, Apple Watch collects data on environmental sound levels which are used to calculate an average daily environmental sound exposure level.

Using data from ~130,000 volunteers from the Apple Hearing Study who contributed Apple Watch data between November 2019 to December 2022, we estimated the percentage of adults across the United States with excessive noise exposure, i.e., those who are consistently exposed above the 70 dBA average limit defined by WHO and US EPA.

Use the interactive maps below to explore excessive noise pollution by location, age, sex, and race based on the data collected from the Apple Hearing Study. Areas in grey on the map indicate locations with a small number of participants (less than 25 participants), and therefore are not included for privacy purposes.

Noise pollution is defined as any unwanted, distracting, or harmful sound.

Sound waves travel through the air and we can measure the energy of the sound waves that reach our ears in decibels (dB).

We often adjust (or weight) decibels to measure the loudness of sound as perceived by our ears, which we refer to as A-weighted decibels (dBA). Below is a noise thermometer of how loud things may sound at different decibel levels and how long you can be safely exposed to those levels on a given 24-hour day and still be within the WHO and US EPA recommended limit.

Note: An example of the annual WHO/EPA recommended limit for a typical day

The WHO and US EPA recommended limit of 70 dBA is an annual average noise exposure. This is different from a short noise exposure, such as standing near a vacuum for a few seconds, which might also be about 70 dBA. The figure above shows that higher levels of noise have lower safe exposure durations.

Average noise exposures to levels above the WHO and US EPA recommended limits for extended periods are hazardous to human health. This is why we looked at what percentage of American adults regularly experience excessive noise pollution above the recommended WHO and US EPA limit.

Note that in a given year you can have many periods of noise exposure above 70 dBA and still be within the WHO and US EPA recommendations, as long as you spend sufficient time in quiet environments so that your annual average exposure is 70 dBA or less.

To generalize, sound waves travel through air or water and the loudness of the sound waves is measured in decibels (dB).

Decibels can be adjusted to represent the loudness of sound as perceived by the ear, which is referred to as A-weighted decibels (dBA).

To generalize the data in this analysis to the US population, we weighted the data from each state by age (<45 years vs ≥45 years), sex at birth (male vs female), and race (white vs other), from American Communities Survey’s 5-year estimates for 2015-2019.

Average exposures to levels above the WHO and US EPA recommended limits for extended periods are hazardous to human health. This is why we looked at what percentage of American adults regularly experience excessive noise pollution above the recommended WHO and US EPA limit, that is, a 70 dBA average over 24-hours.

While state-level statistics were weighted, metropolitan area statistics were not, they are reported as collected.

The noise exposure estimates for each demographic within each state represent ‘best estimates’ for the overall state population based on Apple Hearing Study data and are limited by our ability to weight data to be more representative of the US population.




Sources: (1) Apple Hearing Study environmental sound level data among ~130,000 Apple Watch users from November 2019 to December 2022, and (2) Census Bureau American Community Survey.




Excessive noise exposure by metropolitan areas

  • Metropolitan areas are major cities with their surrounding towns, smaller cities, and communities.

    Nonmetropolitan areas are neighboring rural areas that do not have large urban cities or center.

Check out the map below to see how many people experience excessive noise pollution in metropolitan and nonmetropolitan areas.

Breakdown by race

There were significant differences in noise exposure grouped by race and ethnicity. Approximately 30% of the US adult population was often exposed to excessive average noise levels.

Breakdown by sex

Breakdown by age

If you think you are experiencing excessive exposures to noise pollution, or your Apple Watch indicates that you have high noise exposures, here are some tips for reducing your exposure:

  • Move away from noisy areas and take regular “quiet breaks” to let your ears and mind rest.
  • When buying new appliances, equipment, or tools, consider buying the quietest possible unit.
  • Wear appropriate hearing protection devices, such as ear plugs and ear muffs, when it is noisy. These devices are designed to reduce the sound that reaches your ears.

If you have an Apple Watch, make it a habit to check your noise levels. For more information on how to use this feature, click here.

You can also download a third-party sound level meter app from your smartphone app store. One example is the NIOSH Sound Level Meter app. Note that the Apple Watch alerts to high noise after a brief exposure period of 80 dBA, not the long-term average noise exposures that are the focus of this update.

Thank you to all Apple Hearing Study participants! Stay tuned for the next study update, or check out our last study update .


References

  1. World Health Organization Guidelines for Community Noise, 1999, https://apps.who.int/iris/handle/10665/66217
  2. US Environmental Protection Agency Protective Noise Levels document, 1974, https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=20012HG5.TXT
  3. Basner M, Babisch W, Davis A, Brink M, Clark C, Janssen S, Stansfeld S. “Auditory and non-auditory effects of noise on health”, Lancet 2014 Apr 12;383(9925):1325-1332. https://pubmed.ncbi.nlm.nih.gov/24183105/