Decibel is a real sound-pressure-level meter β A, C, and Z weighted; LAeq, LAmax, LCpeak; statistical Ln (L10 / L50 / L90); OSHA 8-hour dose accumulator; permissible-exposure-time calculator. Per-iPhone-model offset corrections so readings track an actual SLM within Β±2 dB across the 60β100 dB range. Wear an Apple Watch on a job site, in a club, or in a stadium and watch the live SPL on your wrist. Cross 90 dB and the wrist buzzes. End the day with a PDF noise-exposure report you can hand to HR, your doctor, or a workers'-comp lawyer. No microphone audio leaves the device. Ever. The DSP runs in milliseconds in Apple's Accelerate framework. No subscription "fleet platform," no ads. WHAT'S MEASURED β’ Live LAeq, LAmax and LCpeak β the full SLM toolkit β’ A / C / Z frequency weighting (IEC 61672) β’ Statistical L10 / L50 / L90 percentiles β’ OSHA 90 dB(A) and NIOSH 85 dB(A) dose accumulators β’ Permissible exposure time at the current level β’ 1-second sliding LAeq and 125 ms Fast time-weighting β’ Apple Watch live wrist meter with threshold haptics EXPORT β’ PDF dose report β printable, photographable, suitable for HR or workers'-comp documentation β’ Per-second history chart inside the app PRIVACY β’ No microphone audio is ever recorded, stored, or transmitted β’ No tracking SDKs. No analytics SDKs. No ads. No accounts. β’ Zero network requests during measurement WHO USES DECIBEL β’ OSHA-aware blue-collar workers (construction, manufacturing, oil & gas) β’ Live-sound engineers, DJs, musicians, and stage crew β’ Parents monitoring kids' bedroom and daycare noise levels β’ Wedding / party planners staying within sound-level limits β’ Older adults wanting quantitative awareness of environments SUBSCRIPTIONS β’ Free: live LAeq (A-weighting), large-digit display, 7-day history β’ Pro ($3.99/mo or $24.99/yr Β· 7-day free trial): C/Z weighting, LAmax/LCpeak/Ln, OSHA & NIOSH dose, PDF reports, Apple Watch live meter, unlimited history β’ Pro+ ($9.99/mo or $59.99/yr Β· 14-day free trial): manual Β±5 dB calibration trim, per-microphone profiles Trial: 7 days for Pro, 14 days for Pro+, one trial per Apple ID. CALIBRATION DISCLAIMER iPhone microphones are not Class 1 / Class 2 certified hardware. Decibel readings are intended for personal awareness and screening, not legal regulatory evidence. For legal compliance use a certified meter calibrated by an accredited lab. Privacy: https://leexuanxuan95-dev.github.io/decibel/privacy.html Terms: https://leexuanxuan95-dev.github.io/decibel/eula.html Support: [email protected]