Noise pollution can cause stress and too many flight or fight chemicals in the body. This is a public health crisis that can also make tinnitus or hyperacusis worse. Mapping and measuring real time community noise identifies areas or locations with unhealthy noise levels as well as quiet areas and locations that need protecting. Cities are starting to use noise sensors and mapping systems. People can also use a Sound Level Meter (SLM) mobile app for measuring real time community noise. Local community members who might use this include journalists, noise enforcement or city noise bylaw officers, landlords, building managers, home owners associations, etc.
Noise Sensor Real Time Mapping
For noise mapping, cities can put noise sensors at specific points where there are noise complaints or problems. For example, Juan Bello, a sound researcher at New York University, has placed about 50 noise sensors around Manhattan, Brooklyn, and Queens to record 10 second snippets of sound levels. When he compared time of noise complaints about after-hours construction, 95% matched up to a noise violation measured at the same time by one of the noise sensors. Eventually the sensors will show when noise levels are over limits, and what made the sound.
The Shanghai Academy of Environmental Sciences has put noise sensors at each city block and major noise. Their noise map updates every 20 minutes. Zhou Yude, director of the academy’s noise control engineering research center says real time noise data is best, because noise changes quickly monthly and seasonally depending on different factors, e.g. city construction. The map has already been used to find hidden noise sources like a noisy heat pump on a building roof; the property manager had to do noise control.
In areas with no noise sensors, Zhou said data from other city departments is used to calculate noise levels, e.g. traffic flowrate, car speed, car models or railway timetables and train speeds. After years of doing these calculations checked with on-site verification, error rate is no higher than 3%.
Governments are supposed to use data from sensors to take noise enforcement or noise control action. But most communities have no environmental noise expert and no noise sensors, so nothing is done about community noise.
Auto Measure & Map Sound Level Meter apps
There are SLM apps that measure and map community quiet and noisy areas in real time. Examples include iOS/Android HushCityapp (international) and iOS/Android NoiseScore (USA). Maps are in a central online location open to the public.
Noise Score Live Map
I wish there was something like the Noise Score app for other countries, including Canada. An iOS/Android app with real time measuring and mapping noise data crowdsourced from all around a country and viewed in 1 place. Very useful for the local community. Will local governments use this type of result to target noisy community areas and help plan noise actions?
Auto Measure Sound Level Meter apps
Other apps auto measure the noise but don’t map it. NIOSH has developed a free scientific evidence-based NIOSH SLM iOS mobile app. This is the only app I’ve found that’s still free with required SLM settings to measure community noise. There are also paid SLM mobile apps that pass NIOSH acoustic standards. Use internationally recommended SLM settings most sensitive to noise damage:
- A-filter or C-filter (measures noise into low frequencies)
- 3 dB exchange-rate
- Fast time-weighting
- 80 dB threshold limit
- NIOSH standard if an option
Noise Damage Public Health Risk
- Hearing, mental, and physical health damage
- Bad health effects include language and learning delays, stress, high blood pressure, anxiety, depression, heart attacks, strokes, diabetes, obesity
- Most vulnerable are babies, children, pregnant women, elderly, shift workers, people with pre-existing illness
- Noise epidemic around world could be causing the rising children’s epidemics of learning problems, high blood pressure, anxiety, depression, obesity, and diabetes.
- Risk highest for night noise causing disturbed sleep
- Highest risk for low income, minority and segregated communities
- Noise sources louder than public health limits raise the overall community noise risk.
(night = 11:00 p.m. to 7:00 a.m. local time or as defined by local authorities.)
- Day = 55 dBA average or softer
- Night = 40 dBA average or softer
Indoors/Outdoors in Industrial/Commercial/Shopping and Traffic Areas
- max 70 dBA avg 24/7
These are just some of the WHO limits including lower day limits inside hospitals, preschools or classrooms. Loudness limits are lower at night to prevent sleep problems and insomnia that lead to serious health and learning problems in people of all ages. See page 17, WHO Guidelines for community noise (pdf) and Table 5.4 Effects of different levels of night noise on the population’s health, WHO Night Noise Guidelines (pdf).
These limits can also be used for neighbour noise complaints, e.g. somebody having a huge loud party, or apartment neighbour playing music or vacuuming after 11:00 p.m.
Photo Credit for noise map: Shanghai Academy of Environmental Sciences
Jan L. Mayes MSc Aud(C) RAud is an international Eric Hoffer Award winning author, audiologist, and hearing healthcare educator. She specializes in tinnitus, hyperacusis, noise-induced hearing system damage, and darkly disturbing, macabre horror fiction.
Learn More How to measure noise with NIOSH SLM iOS app
Learn More Citizen science SLM app crowdsourced noise measurements