An article in The Journal of Acoustical Society of America describes the scientific review of 10 iOS and 4 Android smartphone apps for measuring sound levels. Although 130 iOS apps were evaluated, only 10 apps met their selection criteria, and only 4 out of 62 Android apps were tested. Only a few apps were available on the Windows phone platform, but none met their selection criteria. As a result, no testing was conducted on Windows-based devices or apps.
The results were that
the SPLnFFT app had the best agreement, in unweighted SPLs, with a mean difference of 0.07 dB from the actual reference values. The SoundMeter app had the best agreement, in A-weighted sound levels, with a mean difference of −0.52 dBA from the reference values. For unweighted sound level measurements, NoiSee, SoundMeter, and SPLnFFT had mean differences within the ±2 dB of the reference measurement. For A-weighted sound level measurements, Noise Hunter, NoiSee, and SoundMeter had mean differences within ±2 dBA of the reference measurements.
Read the full paper on the The Journal of Acoustical Society of America web site.