Sound Meter: Decibel & Noise

Sound Meter turns your phone into a decibel meter with NO recording time limit: real-time dB(A) readings, min/avg/max and Leq, A/C/Z frequency weighting, a scrolling level chart and a NIOSH/OSHA noise dosimeter. Measuring needs no account. Sound Meter is free with ads. Sound Meter Pro — a subscription or a one-time purchase — removes the ads and unlocks every Pro feature. CORE METER IS FREE — NO TIME CAP ✓ Real-time level meter — analog needle gauge (30–120 dB) plus a big digital readout, zones: green below 70, amber 70–85, red above 85 dB ✓ Unlimited measurement duration — no session cap, screen stays on ✓ Session statistics: min / average / max / Leq (energy average, the standard for fluctuating noise) ✓ A / C / Z frequency weighting — IIR filters approximating IEC 61672, normalized at 1 kHz ✓ Fast, Slow and Impulse time response ✓ Scrolling 60-second level chart ✓ Raw, unprocessed microphone input where supported — no auto gain ✓ Shows which microphone input Android actually used ✓ Manual calibration ±20 dB in 0.5 dB steps, with a guided screen ✓ Two-point calibration — a quiet and a loud point against a real meter fix slope and offset ✓ Warnings when the microphone overloads, sits at its noise floor or goes silent ✓ Auto-stop timer (1–60 min) and a big-number display you can flip ✓ Safe daily listening time per NIOSH, for dBA readings ✓ Choose an external USB or wired microphone ✓ Reference level cards — from a 30 dB library to the 120 dB pain threshold ✓ "Sounds like" caption under the dBA reading — a whisper, a vacuum cleaner, a chainsaw ✓ Room check — pick bedroom, living room, classroom, office or outdoors, measure 30 seconds and compare with the WHO guide level. Says so when a room is too quiet for a phone to judge ADS AND PRO, PLAINLY • Free shows a banner at the bottom of the main screen and, at most every few minutes, a full-screen ad after you stop a measurement — never while you measure. • Pro: monthly, 3-month or yearly subscription (the yearly plan has a free trial for new subscribers), or pay once for lifetime Pro. Prices show in the app before you buy; cancel a subscription any time in Google Play. • Not ready to buy? Watch a short video to unlock every Pro feature for 30 minutes (ads stay on). PRO FEATURES ★ Session logging — save measurements with charts, notes and event markers; export CSV or PDF, share or save to any folder ★ Up to 200 markers and a note on the noise source per session ★ PDF report with levels, chart, device, microphone input, weighting, calibration and measurement limits ★ Statistical levels: L10 (loud events), L50 (median), L90 (background) and Peak ★ Octave spectrum, 31.5 Hz to 16 kHz, loudest band highlighted ★ Leq per 1/5/15/60-minute interval and a log of every threshold crossing ★ Export all saved sessions to one CSV ★ Compare two saved sessions — Leq, max, average and L90 differences, in dB and sound energy ★ Noise dosimeter — NIOSH REL (85 dBA, 3 dB exchange) and OSHA PEL (90 dBA, 5 dB exchange) side by side: dose % and 8-hour TWA, resumes where you left off ★ Threshold alert — pick 40–110 dB: vibration and red flash when exceeded ★ Per-device calibration profiles — save your offset and apply it in one tap ★ No ads PRIVACY Your audio never leaves your device: sound is analysed on the phone and no recording, sample or measurement is uploaded. Ads come from Google AdMob and Unity Ads, which may use your advertising ID; where the law requires it, you are asked for consent first and can change it in Settings. Firebase crash and anonymous usage reports can be switched off in Settings. PERMISSIONS Microphone, to measure the sound level. Internet, for ads, purchases and crash reports. Vibration, only for the threshold alert. Phone microphones are not certified instruments; readings are indicative (typically ±3 dB). Bluetooth microphones filter audio for calls, so their readings are unreliable. For legal or occupational compliance, use a calibrated Class 1/2 meter.