In 2014, the NIOSH hearing loss team evaluated 192 sound measurement applications (apps) for the iOS and Android platforms to examine their suitability and accuracy in relation to professional sound measurement instruments.
Of the apps the team examined, only 4 iOS apps met the outlined criteria for functionality, features, and calibration capability.
Realizing that most of the apps on the market are oriented at the casual user and lack the accuracy and functionality necessary to conduct occupational noise measurements, NIOSH hearing loss researchers collaborated with an app developer, EA LAB, to create an iOS based sound level meter app that measures and characterizes occupational noise exposure similar to professional instruments.
The NIOSH Sound Level Meter (NIOSH SLM) app for iOS devices is now available on iTunes freely to the occupational safety and health community as well as the general public.
The NIOSH SLM app has many important features, it provides a readout of the sound level using the built-in microphone (or external microphone if used) and reports the instantaneous sound level in A, C, or Z-weighted decibels.
The app also contains some basic information on noise and hearing loss prevention. In addition, the app allows the user to save and share measurement data using the smartphone other communication and media features.
If location services are enabled, the app can utilize the GPS feature to provide an exact geospatial location of the location of the noise measurement.