The live meter below runs on the same calibrated on-device engine as the homepage decibel meter, framed here for SPL terminology — bookmark either; readings and calibration carry over.
What a Sound Level Meter Does
A sound level meter (often abbreviated SLM, and formally measuring sound pressure level / SPL) reports the intensity of sound in decibels (dB) relative to the threshold of hearing (≈ 20 µPa). An online sound level meter does that with your browser's microphone and the Web Audio API — no hardware to buy, no app to install.
Practically, "decibel meter", "sound level meter", "noise meter", "sound meter", and "dB meter" describe the same online capability. This guide focuses on the sound-level / SPL vocabulary professionals use — for the noise-complaint workflow see Noise Meter and for perceived-loudness weighting see dBA Meter.
Sound Level vs Decibel — Same Thing?
- Decibel (dB) is the unit.
- Sound pressure level (SPL) is what is measured (rms pressure vs. 20 µPa).
- Sound level meter is the instrument that reports SPL in dB (optionally A/C/Z-weighted, e.g. dBA).
So "70 dB" really means "70 dB SPL" — a level. For hearing-risk questions the weighted form 70 dBA is expected; for physics comparisons dBZ (flat). Choose weighting in Advanced Controls and always note it. See dB vs dBA and weighting methodology.
How to Measure Sound Level Here
- Open the meter (works in any modern phone, tablet, or computer browser).
- Allow microphone access — processing stays on-device, nothing is uploaded.
- Choose A-weighting for general sound level; C for bass-heavy setups; Z for raw. See dBC.
- Measure 30–60 s minimum; use Leq for exposure, average for typical level, max/peak to spot loud events. See Leq Meter for why Leq is the correct aggregate.
- Keep mic unobstructed, distance documented ("68 dBA at 1 m"), and calibrate against a trusted reference for repeatability (guide).
Understand Your Numbers
- Current — live level right now.
- Min / Max / Avg — session extremes and typical level; Leq — energy-averaged level (exposure metric).
- Peak — highest instantaneous pressure; relevant for bangs/impacts.
- Spectrum / Waveform — split the single dB into bass/mids/treble and time-domain shape.
- Compare against the common sounds chart to sanity-check: quiet library ~30–40 dBA, conversation ~60 dBA, busy street ~70–80 dBA, concert ~100+ dBA.
For accuracy limits, DSP behaviour, and calibration — see Accuracy, Methodology, and Validation. For exposure limits, see Noise Exposure and the Calculator.
FAQ — Sound Level Meter
Is a sound level meter the same as a decibel meter?
What's the difference between sound level meter and noise meter?
What do min, max, Leq, and peak mean?
Can a phone be a sound level meter?
Related: Decibel Meter · Noise Meter · dBA Meter · Leq Meter · Frequency Analyzer