The live meter below is preset to A-weighting. You can switch to C or Z in Advanced Controls at any time.
What Does dBA Mean?
dBA (sometimes written dB(A)) is a decibel value after an A-weighting filter. The filter attenuates very low and very high frequencies where the ear is less sensitive and passes the speech range largely unchanged. The result approximates perceived loudness at moderate levels.
All common noise guidance — 0 dB threshold, 85 dBA 8-hour NIOSH limit, 3 dB exchange, city noise ordinances — is expressed in dBA. Without the "A" you cannot compare your number with published limits: "70 dB" is ambiguous, "70 dBA" is meaningful. See dB vs dBA vs dBC vs dBZ for the full comparison and the weighting curves.
When to Use a dBA Meter
- Almost always. Room noise, street noise, office/home checks, speaker checks at moderate volume, neighbor noise through walls — A-weighting is the correct default.
- Environmental and occupational noise: regulators, building acoustics, and product labelling use dBA.
- When you want a reading that correlates with annoyance and hearing-risk guidance (see Noise Exposure and the Calculator).
Use dBC instead when the sound is loud and bass-heavy (concerts, engines, subwoofers) and you want to see how much low-frequency energy is present; if dBC is much higher than dBA at the same spot, the sound is bass-dominated. Use Frequency Analyzer to see the distribution directly.
How to Measure dBA Here
- Open the meter — A-weighting is already the default; confirm A-weighted is highlighted in Advanced Controls.
- Place the device where people sit/stand, mic toward the source, case not covering the port. See How to Measure Decibels.
- Measure 30–60 seconds minimum and use the average / Leq, not a single instant. The meter shows Leq with true energy averaging.
- For consistency, calibrate once against a known reference and reuse the offset; export CSV/JSON or Journal for records.
Limitations
Calibration improves consistency but cannot make a phone microphone flat like a laboratory condenser mic. For certified work use an IEC 61672 meter.
FAQ — dBA Meter
What does dBA mean?
Is dBA different from dB?
Why is A-weighting used?
Can a phone measure dBA?
Related: dBC Meter · Leq Meter · Frequency Analyzer · Sound Level Chart · Calibration