Sound-Measurement Guide Hub

You get the most from this hub by starting with a live reading, then picking one follow-up. Open the meter, grant permission once per origin, set the phone down with the mic uncovered, and watch current, minimum, Leq, maximum and duration settle over 30–60 seconds. If the number surprises you, the sections below point to the single guide that answers your next question — no account, no download, current Chrome, Edge, Firefox or Safari over HTTPS.

Which guide answers your question

First reading done and unsure what it means? Follow how to use the meter for placement, Fast 125 ms versus Slow 1 s, and reading the five stats plus the 240-point graph. Number looks plausible but you need it tied to real sound? Calibration walks through a same-spot offset against a known reference, why profiles stay device-specific, and when to redo them. Wondering where any browser number comes from? Methodology traces permission, mono Web Audio capture with gain processing requested off, RMS to weighted dBFS plus the nominal +100 dB offset, and why idle input shows "--" instead of a simulated low.

When your readings feel wrong

Two phones disagreeing by 8 dB in the same room is normal before calibration — capsules, gain and cases differ that much. Accuracy maps the floor below roughly 30 dBA where rooms read high, clipping near 95–100 dBA, weak bass, and why whole numbers beat decimals. No bar moving at all? Microphone troubleshooting covers denied permission, busy or missing inputs and disconnected headsets. Quiet-room number stuck high? The raw-input checks in microphone noise floor test and background noise test separate self-noise from real sound, while dBFS vs dB SPL explains why negative digital figures and room levels share a name but not a reference.

Putting numbers to use without overclaiming

Everyday comparisons belong on the decibel comparison chart from near 30 to 120 dBA, with dB vs dBA sorting A, C and Z picks from the dominant band. Time-weighted thinking lives in noise exposure and the noise exposure calculator: 85 dBA across 8 hours, halving time per 3 dB, calm below roughly 70 dBA, screening only with formal calls left to Class 1 or Class 2 hardware. Phone-specific placement sits in using your phone as a decibel meter, spectrum reading in frequency analyzer guide, and data handling in privacy — local sessions capped at 20, CSV or JSON with dB values only when calibrated, usage-only analytics.

Open the online decibel meter →