How To Measure Noise Pollution using Free NIOSH Sound Level Meter Phone App

[updated 04/15/18] I think the general public should be able to use a free reliable SLM (Sound Level Meter) phone app for measuring noise pollution. There are lots of apps out there, but many don’t take accurate noise measurements, and most aren’t free. Most that look free actually cost money to change the default settings to internationally recommended measurement settings most sensitive to noise damage.

The only accurate free one I’ve found is the NIOSH SLM iOS app. I don’t know if they’re coming out with an Android version. NIOSH developed this SLM app to be freely used by the general public, not just the workplace safety and health community. I’ve been using it for about 6 months now. It’s great for measuring noise pollution or product noise e.g. tools, appliances, etc.

Download the NIOSH SLM iOS app and change default settings to internationally recommended measurement settings most sensitive to noise damage:

• Standard NIOSH
• Threshold level 80 dB
• Exchange rate 3 dB
• Time weighting Fast
• Frequency weighting A filter

Currently C-filter frequency weighting is not available on NIOSH app to measure dBC avg. The C-filter is sensitive to total noise risk including low frequency and vibronoise that can cause imbalance, tinnitus and worse NIHL than from noise alone. C-filter can be set on this app, but only to measure instantaneous level.

Total run time = how long noise measured.

Instantaneous Level Quick Scan (big numbers on screen) = current noise level
Loudness of noise as it happens. dBC avg if C filter set. dBA avg if A filter set.

LAeq = dBA avg
Average noise over time measured. Measured in dBA no matter which filter set. Average includes max or peak noise loudness over time measured.

The more constant the noise, the less time you need to measure. If the blender is buzzing on high, it’s going to be about the same loudness no matter how long you measure. If it’s an up and down or off and on type noise, you need to measure long enough to get a sample that represents the noise that was in your environment e.g. airplane flying overhead.

If C filter is set, and instantaneous loudness is 10 dB louder than the LAeq average noise, there’s a lot of low frequency and vibronoise that can cause health damage.

Max level = dB Max
Highest or peak loudness level that happened during measurement time. Automatically included in the LAeq dBA avg. General public doesn’t need to measure Max separately. If you accidentally bump the mic on the phone, app will measure a big Max that isn’t from actual noise. Max is mainly for general interest e.g. how loud does your dog bark for dinner? My dog’s dinner bark is 105.6 dB Max level.

LCpeak = Don’t use it. Faulty. Measurements too high.

TWA = General public should never use TWA. Only for 8 hour equivalent work shift. Calculated TWA will always be less than measured dBA avg.

Dose % = Don’t use outside of workplace; only applies for 8 hour equivalent work shift.

NIOSH App Notes:

• Buttons from left to right are: Start measuring, Stop, Delete current data, Save on app and Upload.
• Before measuring you need to Delete current data.
• The app needs Wi-Fi or cellular to work.
• When you save noise measurement results, they save sorted by date with dB TWA shown; which will be blank for shorter measurement times.
• Operator/Location Information for saved data on app won’t let me edit it. I’d like to be able to make notes on what I measured and any factors that could affect results. If anybody figures this out, please let me know in comments.
• If you have any problems with the app, contact NIOSHNoiseresearch@cdc.gov. Please include the model of your device and iOS version.

Based on noise damage risk criteria and WHO noise pollution guidelines (1999; 2009):

High Hearing Health Hazard
hidden hearing nerve damage-tinnitus-hyperacusis-hearing loss

at and above 75 dBA avg, day-night chronic noise

High Physical & Mental Health Hazard
insomnia-learning delays-anxiety-depression-heart disease-obesity-diabetes-dementia

55 dBA – 75 dBA avg, day-night chronic noise

Moderate Physical & Mental Health Hazard
insomnia-learning delays-anxiety-depression-heart disease-obesity-diabetes-dementia

35 dBA – 55 dBA avg, day, chronic noise
30 dBA – 55 dBA avg, night, chronic noise

https://www.janlmayes.com/transportation-noise-pollution-is-a-2018-public-health-crisis/

Night noise guidelines for Europe WHO/Europe, 2009

Burden of disease from environmental noise. Quantification of healthy life years lost in Europe WHO/Europe, 2011

Guidelines for community noise (PDF) WHO, 1999

Jan’s Book Portfolio

Jan L. Mayes MSc writes horror fiction and non-fiction, and is an international Eric Hoffer Award winning author, blogger and audiologist specializing in noise, tinnitus-hyperacusis, hearing health education and plotting murders. Her writing has been featured at Tinnitus Today, Communique, silencity.com and The Horror News Daily.

Subscribe to Jan’s Blog to be the first to know about book giveaways, free promotions, exclusive short stories and coping tool reviews.
Contact: author@janlmayes.com
Goodreads Author Page: https://www.goodreads.com/JanLMayes
Twitter fiction-non-fiction @janlmayes https://twitter.com/janlmayes
Twitter tinnitus-hyperacusis @tinnitustoolbox https://twitter.com/tinnitustoolbox
Facebook Author Page: https://www.facebook.com/JanLMayes-Author

janlmayes.com/guide-to-reported-db-noise-level-measurements/

janlmayes.com/quiet-activist-must-have-free-ios-phone-apps-to-document-noise-levels/

Pipedown The campaign for freedom from piped music in restaurants, grocery/retail stores, hotels, etc.  Spreading in UK and Australia; volunteer community pipedown chapters needed in USA,  Canada and other countries.