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. View the video for a demonstration of the app’s features.  The weighting is user-selectable and can be accessed in the “Settings” screen.  The app also reports the main metrics that are of importance for proper occupational noise measurements – mainly the run time (total time), the A-weighted Equivalent Sound Level (LAeq), the Maximum Level measured during the current run time, the C-weighted Peak Sound Pressure Level (LCpeak), the Time-Weighted Average (TWA) and Dose.  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

Key Features
Developed by experienced acoustics engineers and hearing loss experts
Tested and validated (accuracy ± 2 dBA) according to standards in a reverberant chamber at the NIOSH acoustics lab – the only proper  method to validate accuracy
Meets Type 2 requirements of IEC 61672:3 SLM standard when used w/ external microphone
Provides the most relevant metrics found in professional sound instruments today. Averages such as LAeq and TWA, Max and Peak Levels, Noise Dose and Projected Dose according to NIOSH and OSHA standards, and all three major weighting networks (A, C, and Z
Capability to calibrate either internal or external microphone. Reporting and Sharing data
Up-to-date informational screens on what noises are considered hazardous, how to conduct a noise measurement, how to properly select a hearing protector, and guidelines for preventing hearing loss
Technical support available directly from NIOSH hearing experts