"There's an app for that."
Back in 2010, Apple told us so (and trademarked the catchphrase.)
So, if you're asking the question "Is there an app for my phone or tablet that can take sound level measurements?" The answer is yes.
But here's the catch: According to an article in the December 2014 issue of the AIHA Synergist, More Apps for the EHS Professional, if you need to prove the validity or accuracy of your test data to a regulatory agency or in a court of law, the data produced by your phone or tablet won't meet the required standards.
In fact, Faber Acoustics, maker of the iOS app SoundMeter, state clearly on their website: "Although it has been designed to do so, SoundMeter has not been shown to meet ANSI or IEC standards for sound level meters. These standards require conformance of the entire measurement system, including software, hardware and microphones. "
They also further explain "iOS mic inputs generally pass through a high pass filter which may significantly attenuate frequencies below 200 Hz."
So, if you want to run a quick test to see if your sound levels are anywhere close to a point of concern, using an app as certainly better than nothing. But, if you need to prove to OSHA or some other regulatory body that you're meeting exposure level standards, you'll want to use a real sound level meter that meets industry accuracy standards.
Need to measure workplace noise exposure or sound levels in indoor or outdoor environments? Check out our list of datalogging sound level meters and personal noise dosimeters available to rent for your area sound level and personal noise exposure surveys.