The 60-second quick start (then read the details)
Open the homepage meter, click Start Measuring, grant microphone permission once, and place the device where people actually listen — ear height, mic uncovered. Stay silent, wait 30–60 seconds, and read the average or Leq — not flickering instants. Note place, distance, weighting and duration (“bedroom night, 35 dBA Leq 60 s”). That routine alone beats most app measurements. Everything below makes it trustworthy across devices and rooms.
Phones (Android and iPhone): strengths, differences and traps
Smartphones are ideal for spot checks: always with you, decent capsules for 40–90 dB, GPS and notes built in. iPhones resemble each other more closely (fewer models, similar mics), so two iPhones often agree within 3–5 dB; Android devices scatter widely by maker, model, case and settings — 5–10 dB disagreements on the same sound are normal uncalibrated. Neither is absolutely calibrated out of the box.
The three phone traps: cases covering the mic pinhole (often on the bottom edge — check yours — costing up to 10 dB), grip and handling noise (2–5 dB shifts as you squeeze; set the phone down instead of holding it for background readings), and hidden processing (noise suppression erases steady bass, AGC rides levels). Fixes: remove bulky cases or align cutouts, lay the phone on a soft cloth at ear height, enable airplane mode plus Wi-Fi for long sessions to stop calls interrupting, and keep the screen on — mobile Safari pauses background tabs quickly. Always note the device (“Pixel 7a, no case”) so later comparisons stay fair.
Tablet, laptop and desktop: when big wins — and what fans cost
Tablets suit long sessions (classroom full lesson, office half day) via battery and a stand. Laptops and PCs shine at analysis: big spectrum, history graph and CSV export at a glance — ideal for musicians, podcasters and workbench DIY comparing before/after. The catch: laptop fans add 35–45 dB of background and keyboards add clicks — for quiet rooms, move the laptop away and use a wired external USB microphone placed at the listening spot, noting what you measured with. Lower fan curves or passive cooling during critical minutes helps, and closing other tabs avoids notification dings ruining a Leq.
Browsers compared: Chrome, Edge, Safari, Firefox
Chrome and Edge (desktop and Android) give the most stable Web Audio chain and clearest permission dialogs — recommended for first measurements. Safari (iPhone/iPad/Mac) works well but asks more strictly, shows a mic indicator, and suspends background tabs sooner — keep the tab foreground and screen awake, and re-grant after iOS updates. Firefox measures reliably with permissions tucked behind the padlock icon — click it if the prompt never appeared. Universal rules: latest version, single microphone tab open, reload once after changing permissions, and grant “allow” (not “allow once” if you measure daily) so prompts stop interrupting sessions. Full privacy notes in privacy and signal details in methodology.
Microphone placement: the pinhole, distance and wind
Find the pinhole first — bottom edge on most phones, beside the camera on some tablets, near the hinge on laptops. Keep it clear, aim it toward the source at ear height, and fix distance: 1 metre for appliances and speakers, seated head position for rooms, 30 cm off the wall (never pressed against it) for neighbour noise to avoid structure-borne exaggeration. Outdoors, wind is the invisible enemy: a hand held as a shield nearby without touching, or a cheap foam windscreen, cuts artefacts by 10+ dB. Indoors, switch off disturbers first (HVAC boost, second speaker, humming fridge you stopped hearing) and measure the room as people use it — doors as they are, not staged.
Every reading needs four companions: place, distance, weighting (dBA default; add dBC for bass complaints), and duration with metric (“kitchen, 1 m from fridge, 52 dBA Leq 60 s”). Without them, even accurate numbers are incomparable. Log them in the Noise Journal with exports.
Calibration in 5 minutes: from estimate to personal instrument
You need a reference: ideal is a 94 dB pistonphone calibrator at 1 kHz; practical is a trusted second meter, a calibrated speaker tone from an audio lab, or a well-documented appliance level. Place both at the same position, measure the same 30–60 seconds average, compute reference minus reading, and enter it as the stored offset in the Calibrate dialog. Example: reference 94 dB, your phone reads 89 dB — offset +5 dB. Retest: the same tone should now read ~94 dB. Recalibrate after phone or OS changes.
Realistic expectations: calibration removes most inter-device bias and makes before/after and device swaps far more stable — but it cannot fix frequency-response gaps (bass still under-reads) or turn a consumer capsule into an IEC 61672 instrument. For legal, workplace-compliance or product-spec numbers, hire certified kit and professionals; for everyday decisions, a calibrated phone plus Leq is genuinely good. Method in the calibration guide, limits in accuracy.
The 7 top mistakes — and the fix for each
1. Covered mic — check case and fingers; retest uncovered. 2. Quoting 3-second peaks — always use Leq or average over 30+ seconds. 3. Talking or typing while measuring — silence yourself; your voice adds 10–20 dB. 4. Comparing different distances — fix distance and note it. 5. Forgetting your own devices — fans, HVAC, second screens off first. 6. Only dBA when bass is the complaint — add dBC and spectrum screenshots. 7. Measuring once and judging — repeat from two spots, export, journal, average. Avoid these seven and you measure better than 90% of occasional users — and your landlord, teacher or bandmate will notice the difference in how seriously your numbers land.
Next: run a home survey project, check anchor sounds, and learn when levels become harmful. Reference only — not for compliance decisions.