Yes there is an App for that, new NIOSH Sound Level Meter
NIOSH has released a new Sound Level Meter app for your iPhone or iPad. It’s called NIOSH SLM, it’s available through iTunes, and it’s free. Details about the app and the testing criteria, test results, and other pertinent information are contained in NIOSH’s January 17th blog post. The app carries the NIOSH logo, so it’s a NIOSH product.
As a quick summary, it’s pretty slick. It has all the basic functions of a standard Type 2 Sound Level Meter – run time, sound level, maximum value, dose, TWA, etc. It can save runs for later study and it has a reporting function for emailing results. I downloaded it to my iPad and was up and running in no time. After about an hour, I had it down pat. There is an online user’s manual, but it isn’t all that necessary. Tapping the icons, which also have captions, is really all you need to do.
When you open the app, it goes directly to the Sound Level Meter and immediately starts taking measurements – no NIOSH logo, no software version number, etc. On my iPad, the numbers are really prominent which is handy in low-light areas. At the bottom of the Home screen are four (4) buttons corresponding to the sound level meter, saved data, noise information, and settings. Tapping a bottom button takes you to that screen.
The home screen looks like this:
The large numbers are the sound levels. Scrolling up in the middle parameters area shows the TWA, dose, and projected dose. Tapping on a parameter changes the display to that parameter.
Some great things about it:
- The sound level is instantly displayed when you open the app.
- No pop-ups, no advertisements, and no upgrades to purchase. Enough said.
- As an iPad app, there’s not a lot of extraneous information that clutters up the screen. You see only what you need to know (run time, instantaneous SPL, maximum SPL, equivalent 8-hour exposure, dose, projected dose, etc.). This is great when you are out in the field and just need to see at a glance what the numbers are looking like.
- It has a Settings screen that allows you to change the threshold, exchange rate, time weighting, and scale.
- There is a calibration feature that allows you to check your microphone’s response.
- You can email the results immediately or save your work and email the results later.
Things for later releases:
- There’s no easy way to attach a picture to the report. It can be done, but it is a bit cumbersome.
- The report doesn’t list the measurement parameters (e.g., weighting, doubling, threshold, etc.). As an industrial hygienist, it’s always nice to know the parameters behind the measurements.
- The Standard tab in the Settings window doesn’t distinguish between OSHA HC and OSHA PEL. I can get there by manually changing the threshold from 80 dB to 90 dB or vice versa, but it would be nice for the app to do it for me (I’m just lazy, I guess).
A couple of caveats:
- I wouldn’t use this app in place of a Type 2 calibrated Sound Level Meter if I’m testing for regulatory compliance. The app isn’t there yet and isn’t designed to be used for that purpose. I would, however, use this app as a general guideline for sound level.
- NIOSH recommends that a calibrated, external microphone be used in place of the internal microphone because the accuracy is better with an external microphone. I didn’t use an external microphone and found that my iPad’s internal microphone had sufficient sensitivity and response. Since I’m not using this for regulatory compliance, I’m sticking with my internal microphone.
One final thing. This app is currently only for iOS which means it can’t be used on android systems – only iPhones and iPads. According to NIOSH, iOS systems are cross-compatible and optimized for audio applications. With Android systems, microphone specifications are different for the many different manufacturers which makes standardizing the Sound Level Meter app across the Android platform not possible at this time.
The bottom line. It’s a great app and I highly recommend it.