NIOSH Sound Level Meter

4.7 (12.8K)
17.2 MB
Age rating
Current version
Last update
1 year ago
Version OS
12.0 or later
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User Reviews for NIOSH Sound Level Meter

4.68 out of 5
12.8K Ratings
3 years ago, 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. Thanks! LT
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1 month ago, miko-¥!
needs frequency measurment
trying to follow my counties guidelines (clark county ,aka las vegas NV )regarding sound ordinances . decibel measurements are great . but the maximum permitted decibel level changes depending on the frequency of noise . the higher the frequency the higher the maximum decibel level is , lower freq lower decibel limit. unless i am misunderstanding how frequencies are measured or how to use all the features of your app. i see there is 3 diffirent letters for measuring specific frequency ranges . “z” being the lowest frequency range, and “a” is the highest range. cant rememeber the middle one … “b” i think? . tried all of them with little change in readings being given and not entirely understanding what changes when I change the “frequency letter”in your app . notice a slight difference in measurement but because i cant isolate specific frequencies . i get a range of frequency measurements all at once if measuring how loud system is heard outside of where the music is played . then hard to tell what frequency is being played at how many decibels . therefore would be hard to show(unless i just dont understand how to do this with instructions provided with the app) ,or “prove” my music is not exceeding my counties sound regulations. especially any law enforcement that decided to show up and investigate a disturbance or noise complaint. dont know if this app could help with that. ——miko——————————1
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3 years ago, Robert_3rd
Can save environmental noise data to Apple Health
Great app to use if you don't have an Apple Watch or can't afford one. It will keep the screen on and drain the battery, but I don't use my iPhone as my main phone. I use it as a portable media player and now also as a decibel meter at work. I run this app while I'm working --with the phone in my pocket, with the mic up and sticking out of my back pocket-- my warehouse job. I save the data to the Health app to make sure my job isn't causing me irreversible hearing damage over time. I'll also run it in public places such as grocery stores, and in the car while driving.
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7 years ago, Me 1024
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.
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1 year ago, Fototico
I wonder about it’s accuracy
I wonder about the accuracy of this and other apps. I compared the readings I was getting from this app in my iPhone 14 Pro Max and the readings from the Apple Watch. This app consistently kept showing noise levels to 5-7 bd louder than the watch. So I went online and ran a search to see of anyone had tested the accuracy of the Apple Watch’s noise meter. It appears that people tested the watch with a dedicated noise meter device, and it was off by like 2 or 3 tenths of a db. Pretty darn good if you ask me. But to be fair, I compared the reading of two other apps and they also were all over the place. One showed reading about this app. Another between this app and the watch’s reading.
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6 years ago, AcousticsProf
The only truly free and most accurate decibel app
No ads, no in-app purchases, no hassle to upgrade every 10 seconds, fully-featured unlike the other top apps that entice you with a single feature but force you buy an upgrade to get the rest of the functionality of the app. Developed for professional users who are serious about acoustics by the top hearing lab in the country, if not the world. I use a Larson-Davis 831 for my daily work and have compared many apps to my SLM and though I was always skeptical about apps, this one is the most accurate out there.
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3 years ago, ebsound
My preferred noise measurement app
As a researcher in the field I have been following the scientific literature on noise apps for the past five years and more. This one has been tested and reviewed and shown to perform with good accuracy. I have also worked with it in my own laboratory to verify its performance. It continues to be updated, the latest update including calibration for the iPhone SE and iPhone 12 series of phones. Thank you NIOSH for an excellent tool.
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1 year ago, groundflax
Seems accurate, but stops audio for some reason
I downloaded a couple other apps before this one and this was the first that have anywhere close to believable readings so I think it’s accurate. However, when you open the app it stops whatever you are listening to on your phone! Which is bizarre bc this is supposed to help you measure the noise level around you and you can’t do that since it turns off a big source of noise first! So that’s very unfortunate and weird, but it’s a good app for other situations.
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3 years ago, Jane Weidland
External Microphone not possible
I have tried now on multiple separate phones with the software freshly installed. I cannot get the program to recognize any external mics I plug-in to have better accuracy than the in accurate internal mic. I would like to put a mic and they can actually placed on a calibrator. I’ve sent a message to the Company that has developed the software and I will be looking forward to hearing back how one can properly connect an external microphone to the software. It is completely ineffective to use the internal Apple microphone so that is no option at all for any real use of this software.
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5 years ago, smileitspaul
Just what I need, nothing I don’t.
The app developers really deserve praise for creating a completely free app that doesn’t blast me with ads, beg me to upgrade, and generally distract me with BS when I try to use it. The interface is clean and easy to navigate. It seems very accurate, especially for what I need which is basically just comparing noise levels relative to one another. It never glitches or quits unexpectedly. I’ll stay loyal to this app, it is exactly what I needed.
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3 years ago, PhilTheAppUser
Very easy to use and well designed
I download this app and within 15 minutes it was for using it and fully understanding I had a couple of tech-support questions I emailed the company in Netherlands I believe and they answered within a day and they answered more than satisfactory with links and pictures and graphics. The application, the developers, and the tech-support are WONDERFUL!!! I can’t recommend this more highly — it’s the best dB sound meter that I have used. As I understand it if you buy one of the external microphones with your calibrated to the app and then you calibrate the dB Meter following their procedures, the results are legal, and from what I understand, admissible in court or other type of legal proceedings. Please don’t quote me on that part, but that’s my understanding. Thank you! Phil, Colorado
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2 years ago, jdapp
Free db meter from my taxes!
Just got this decibel meter and it was one of the few that didn’t cost anything, have in app purchases AND no tracking! Turns out that NIOSH (national institute for occupational safety and health) is part of the CDC and was developed in conjunction with EA Lab, Inc. (probably more likely by EA under contract). Anyway, it’s free and seems pretty good and feature rich. Surprised to get something from the App Store AND government for free that’s actually pretty good!
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9 months ago, 2 Channel
I have little experience with sl meters so this goes with a grain of salt, but after using a Radio Shack analog meter for years this has been eye opening and educational. I don’t use this for anything but setup and comparison of home equipment. I can’t attest to the accuracy but it seems reliable enough for my needs. The neat part is the extra measurements it’s capable of, most of which I have yet to learn about.
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4 years ago, ryanollie08
Very effective
I have used this app for a very long time now for the laeq functionality to find long term (30ish minute) average volume. I also spot check consistently to watch for short term exposure levels. The app is surprisingly close to my calibrated dB meter! Usually within .5 dBA, as long as the room volume is under approximately 95dBA. I foresee myself using this for a long time to gauge live music volumes.
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5 years ago, Ethan Proulx
Love this app
I use this app all the time when I go to concerts and I love it. It does exactly what I need it to do. My dad knows a lot about safety in the workplace and other environments so I like to show him how loud it is when I go to certain events. Little Bug: When swiping to delete and not letting go but swiping back as to cancel the action the app crashes. Just a little bug I found!
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4 years ago, jonanderson335
so much fun
this game is so much fun! I would give it 10 stars if I could. my high score is 132.2 dB. Let me know if anyone is able to beat it. this game is a family favorite and will be sure to have the entire group laughing. my family loves to play this game as we wait to be seated at restaurants. It is also a lot of fun to play on long car rides and flights!!
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5 years ago, Indiegrrl2367
The best and only good sound meter app
Well made, well designed, free and without ads or other annoying BS. As or more accurate than the inexpensive handheld sound meter I have. The only feature I wish it had was the ability to auto save sessions - I often forget to press the save button and then it’s gone forever! Besides that, great job NIOSH.
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3 years ago, Orca688
Sound Judgement
I work in broadcast engineering for a faith based, global TV network. When live music is played in the studio, it is often so loud it hurts; which tells me it is hazardous noise. This application is the most scientific sound measuring tool available for cellular phone use; only commercial grade dB measuring rigs are better.
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2 months ago, memyselfandimac
External mic not working
Love the app, great design and simplicity. But want to use it with my lightning port mic. It shows external mic as a option but when I select that it always jumps back to internal. I uninstalled app, connected external mic, tested it with voice memo and other apps and it works just fine. Then reinstalled NIOSH app gave it permission to access mic but it still won’t use external mic. Have rebooted phone. Still not happening. Iphone8 running 16.7.7
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2 years ago, Sarah-Double O Three
Simple & Accurate
I downloaded a few apps before this one and of course, they wanted a subscription after a few-day trial. I’ve completed a few different sound tests on my iPhone and the results are legit. Although I did notuse an external mic, I still had great results! Thanks! This app is awesome!
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4 years ago, Yochiii
Play & Pause doesn’t seem to work
I can’t tell what the play or pause does as when I click on either one, the noise measurement continues to respond. Then, sometimes the app would freeze and not record any measurements whether I clicked on play or pause. I also gotten situations were the app is responding to sound and updating the metrics in the stat below but the main display where it displays the instantaneously levels just shows —.
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3 years ago, sandiagold
When it works it’s great..update
Update seems to have fixed something, app is working great thank you. While I won’t pay a monthly fee I would pay for this app if it consistently worked. Unfortunately you never know when it will or won’t work.
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3 years ago, beibin79
Concise, clean, convenient, and free app
This is the best sound meter app I tried so far. Thanks so much for NIH developing and funding this app. It’s a lame that this app is not recommended when I search for “sound meter”. Apple should make this tool *STAND OUT” when people are searching relevant apps. The deci**** X and other apps should de-prioritized.
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5 years ago, JuniorDank
From a real person with nothing to gain from this.
Used it and it made “correct seeming” readings it went up with noise and back down. I wouldn’t trust it for professional work(school). But this is FREE no subscription required before it starts. 100% recommend it Disclaimer: Original post written after 3 app starts and 20 min spent on app.
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6 years ago, XxxsomeguyxxX
Easy to use and free
Great app. Upon opening it provides instructions on use. It’s fairly simple with only a few options to choose from with no annoying ads of any kind. It was also the only app I’ve used that makes calibrating an add on mic easy and accurate. Great use of tax money.
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3 months ago, Vato Loco 2333
Keeps going blank
- -:- - keeps popping up. Had to delete the app. Will try to download it again later and see how it works…. Update: Creator contacted me and informed me how to fix the issue. Easy to do. Now, if I have any issues, I know what to do. 5 Stars
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4 months ago, Podpuzzled
Can the survey data be loaded into the Apple Health app
The data is easy to collect, but I am a retired 85-year-old certified safety, professional, and not familiar with the current definitions above and beyond the basic noise level. I would like to enter this information into my Apple Health app.
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4 years ago, Ygiiop
The actual free one
Don’t bother downloading the other apps that come up in search. Almost all those require you to sign up with credit card before you can even use them. Garbage This app is by far the best and easiest to use. Don’t hesitate and just get this one.
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2 years ago, C_phl
Gone haywire?
I’ve used this app for a while and been happy. In the last few weeks something has gone haywire with readings that are unlikely or impossibly high. Sitting in a quiet room with no background noise (you’d expect ~30db) registers as 50-60db, for example. The readings are now ~20db higher than my Apple Watch (which I know isn’t perfect). I’ve deleted and reinstalled, but no luck.
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3 years ago, Jack Rock IV
I love this app. Genius.
This measures decibels and is incredibly accurate. We tested it agains some very high prices scientific equipment, and it always came within .5-1 decibel. Very well done. It also does a great job drawing attention to how loud our environments actually are, and the toll that’s taking on our ears. Excellent App!
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6 months ago, lifeinfusion
Very good but with one big issue
It takes very accurate sound measurements, but from time to time the app will stop displaying the current db reading and show a blank - -.- reading. I hope this can be fixed in the next update. Otherwise a very useful app.
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6 years ago, Neilax
It’s more accurate than most apps
It’s more accurate than most apps, but it’s still less accurate than a real decibel meter. It tends to show higher decibel numbers than a real decibel meter would show for a particular noise. For example, it showed 132.6 decibels when I screamed!!! I screamed in front of a RadioShack decibel meter and that only showed 114 decibels.
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2 months ago, 051Saw
User interface not user friendly
The app is easy to start, but saving the reading data is not easy to do and you can loose all the data. Could be fixed by making the record button change to a save button when recording data.
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3 years ago, rpasea
Great app
I’m an architect who often has a need for a quick measurement of dB levels in and around the built environment. This is the best app I’ve found for doing what I need: recording dB levels and sending reports to document.
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4 years ago, tomjerry21
iPhone 11 support?
Worked well with my iPhone 6 a few years ago. Now have an 11 series iPhone. Was it also tested on new phones? I can’t find that information anywhere. Update: actually heard from the developer. It works with the 11. Awesome app!
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8 months ago, WillyWonkas School4Fatbois
I use this almost every day, every gig
Seriously the reason I have an iPhone at all. Mixing music every day, in my apartment, on the gig, it helps me keep my ears calibrated and put hearing safety first. Highly recommend.
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7 years ago, Threebeards
Decibel meter
Probably the best you'll get for your phone without plugging in an external microphone, which you can also do with this one anyway. Like it says it's from NIOSH it's free it has no ads and it's not trying to sell you it's other apps. Download this one.
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6 years ago, BluesMusician
Save your hearing!
This app gives lots of data to know if you are damaging your hearing. I had no idea the live music was so loud! I wish I had this app years ago, to prevent my hearing loss and tinnitus. Also, use good hearing protection to prevent permanent damage. The damage cannot be undone!
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5 years ago, MKPainter
NIOSH Sound Level Meter
This is the best sound level app I’ve ever used. It tells you everything to know about what you’re hearing. I have earplugs that reduce 35 dB and when the app gets to that level I can hear nothing. I do highly recommend it. Martin
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4 years ago, WJR1989
Well-written elegant app
This application is VERY well suited to applications where human exposure to potentially damaging noise levels can be accurately AND provide actionable data from the standpoint of industry-recognized personnel exposure/safety measurements. It’s ability to EXPORT measured data is also very valuable.
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3 years ago, Liz Garcini
Very helpful
I have being living in stress and very sick, Always wanting to measure the noise level coming to my apartment. This digital sound meter came right helpful . It’s very accurate.
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5 years ago, FocusSeeker
Excellent SLM app
This app plus a calibrated mic and an iOS device provides capabilities that otherwise cost many hundreds of dollars more. The only feature that I wish it had is the ability to report z-weighted Leq.
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5 years ago, AnonGod
Best Free Speaker Calibrator!
All of the other SPL apps are trash. They’re full of ads and only care about money. This app is free and is of a much higher quality than Decibel X & every other one I’ve tried. Highly recommended.
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3 years ago, Rpgustavson
Won’t work after minimizing
Cannot resume measurements after being minimized. Have to actually “close” before it can be used again. Not a biggie, but annoying.
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1 year ago, Ican'tfindanunusednickname
Tons of helpful info and features
Extremely helpful even for me as a sound enthusiast who wants to protect their own hearing
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5 years ago, a_vasquez
Almost there
Works beautifully but sorely lacking iPad optimization. Would also like to see Apple Watch app as well, but mainly iPad native app. Developer yes I know it can be ran on iPad but I want native iPad resolution. Been asking this for a while along with others. I’ll change my rating when we get this. Please consider it!!
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6 years ago, Granny to two
Doesn’t do anything, just this “error”. P. S. Nope. I tried re-loading the app. It didn’t request permission to use my microphone. Tried using it, no luck. Went to settings to see if I could connect the microphone manually, but NIOSH SLM isn’t one of the apps that has requested permission to use my microphone. Deleted it again. I use dB Meter Pro - it works, is simple to use and gives similar results to sound level meters I use at work.
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1 year ago, tripleD&doubleDs
In another review they say it can’t work while music is playing on the iPhone due to proximity of the iPhone speakers to the microphone. Fine. Then why disable it when the phone is simply a source for speakers utilizing airplay!?! Trying to make sure my stereo isn’t too loud but this is zero help. Doesn’t seem like a difficult thing to fix.
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4 years ago, Duckin33
App set up isn’t readable
I have had this app a little over a month and have sent in an email and tried to get help or to ask them to fix it. They have neglected to return email so that I can know what’s happening with it. I still can’t use the app and have deleted it off my phone for negligence on the part of the programmers communication or fixing the app! Very unprofessional!!!
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8 months ago, intuitive_displays
Every app should be like this: simple, useful, and easy to use. I used this app to match the effective volume/SPL of my speakers and the results speak for themselves!
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