Sound Meter is in the 4th set of the Smart Tools collection. Have you ever suffered from the noise of the neighbors? SPL(sound pressure level) meter app uses your embedded microphone to measure noise volume in decibels(db), and shows a reference. REMEMBER! Most smartphone microphones are aligned to human voice (300-3400Hz, 40-60dB). Voice calls do not require high-performance microphones. Therefore the maximum value is LIMITED by manufacturers, and very loud sound(100+ dB) cannot be recognized. Moto G4 (max.94), Galaxy S6 (85dB), Nexus 5 (82dB) ... You can easily check if my voice is loud in a lecture or if the TV volume I turned on is not too loud. See 6th images. I calibrated major Android devices with an actual sound meter (dBA). You can trust the result in routine-noise levels (40-70dB). Please use it as an auxiliary tool. * Main features: - Upside down mode - Level notification - Line-chart duration - Material design * Pro version added features: - No ads - Vibrometer - Statistic menu - CSV file exporting * Do you want more tools? download [Smart Meter Pro] and [Smart Tools] package. For more information, watch YouTube and visit the blog. Thank you.