iPhone Screenshots


This award-winning app combines the best features of professional sound level meters and noise dosimeters into a simple, easy-to-use package.
- Developed by experienced acoustics engineers and hearing loss experts.
- Completely FREE – No ads, no limited features, and no in-app purchases.
- Tested and validated (accuracy ± 2 dBA) according to standards in a reverberant chamber at NIOSH acoustics lab – the only proper method to validate accuracy.
- Trusted source and world-class expertise in noise and hearing research.
- Meets Type 2 requirements of IEC 61672:3 SLM standard when used w/ external microphone.*
- Provides the most relevant metrics found in professional sound instruments today. Averages such as LAeq and TWA, Max and Peak Levels, Noise Dose and Projected Dose according to NIOSH and OSHA standards, and all three major weighting networks (A, C, and Z).
- Capability to calibrate either internal or external microphone. Reporting and Sharing data.
- Up-to-date informational screens on what noises are considered hazardous, how to conduct a noise measurement, how to properly select a hearing protector, and guidelines for preventing hearing loss, all at the palm of your hand.
- Excellent and timely support from NIOSH hearing experts.
- Support for Apple's Health (Hearing) app.

* Celestina M, Hrovat J, Kardous CA [2018]. Smartphone-based sound level measurement apps: Evaluation of compliance with international sound level meter standards. Applied Acoustics, 139:119-128. https://doi.org/10.1016/j.apacoust.2018.04.011

More resources (including instructional videos and a user manual), a science blog, FAQ, and information about how to interpret results can be found on the NIOSH SLM website https://www.cdc.gov/niosh/topics/noise/app.html

What’s New

Version 1.2.4

This version brings various bug fixes. In addition to the iPhone 12 family of devices it supports iPhone SE 2020.

Ratings and Reviews

4.7 out of 5
7.5K Ratings

7.5K Ratings

Satisfied 3 ,

NIOSH sound level meter

I love the convenience of this app, and how simple it is to use.

I have protected my hearing since I was a child when I found out that some of my relatives were very hard of hearing because they had been exposed loud noises in their lives. I still jealously guard my hearing, as I have worn glasses since I was a kid and don’t want to lose a second sense.

When I am exposed to loud noises by people who don’t seem to care, or it doesn’t sound that loud to them because they have already damaged their hearing, it gives me an opportunity to show them that it is loud enough to damage hearing and they need to turn the volume down a bit for everyone’s sake, or it shows me that although I’m uncomfortable, it’s still in the safe zone, and I just put in my earplugs. Or if it’s someone like my husband who is hard of hearing from all his years in construction and not protecting his hearing and needs the volume up like that to hear it, I just hand him the headphones.

I pulled your app out to use it this time because all the hammering going on inside my house right now (a construction project inside my own home) is hurting both my ears and the dog’s, so I was checking to see how much damage is being done and are the dog and I safe without hearing protection.



Disgruntled albatraoz ,

Well done

I have been using this app for over a year and through several updates. It has always worked well and accurately. It has been a useful tool for monitoring the noise exposure and deciding where and when I need to wear earplugs. The only feature it lacks (in my opinion) is the ability to run as a background process with the phone asleep (similar to the way you can play music), which would allow to have the screen off and use less battery when monitoring for long periods of time. Aside from that personal preference, this app has been reliable and helpful. I would highly recommend it.

Diray Acosta ,

Doesn’t Work

I was using it to try out the free version and when I installed it and opened the app for the first time; it showed me readings that were very untrue like 120dB. I know this isn’t right because I was lying in my bed with no electronics on next to me or anything loud at all. I don’t know what the problem is since there’s so many positive comments but it no work :(

EDIT: I thought there could be a free version and a paid version but I guess I was wrong. This review is not for a different app by the way, it was just what the app was showing me. But I do not have a professional microphone attached to my iPad so if you want to say it was that I guess it could be 🤔 yet I doubt it. I will change my review to 4 stars because I am only testing this against 3 other decibal meters and not a profesional machine or a sound that is supposed to be at a specific level.

Developer Response ,

We believe this review is for a different app. The reviewer reports trying a "free version" of the app, but that's all there is, there is no paid version or in-app purchasing, the app is completely free. We believe the reviewer is confusing our app with another. The reviewer also reports seeing 120 decibels in his bed, which is virtually impossible for our app.

App Privacy

The developer, EA LAB, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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