Measurement Integrity
Captures raw, unprocessed audio — bypassing the OS echo-cancellation, noise-suppression and auto-gain that distort every other phone meter.
No account. No cloud. No subscription.
Measure what's really there. a calibrated sound level meter
dB Logger turns your phone into a professional sound level meter, frequency analyzer and noise logger — capturing raw, unprocessed audio for true dBA, dBC and dBZ, a live spectrum, NR/NC ratings, and lossless logging. Free on iPhone and Android.
Built for real measurement
Professional Metrics
Real-time dBA, dBC and dBZ with Fast/Slow/Impulse weighting, plus Leq, Max, Min, Peak and NR/NC single-figure room ratings.
Live Analysis
A live FFT spectrum from 20 Hz to 20 kHz, a 1/1 and 1/3-octave equalizer, a scrolling time-history graph and an analogue dB meter gauge.
Log & Report
Log metrics to CSV and raw audio to lossless WAV, then generate and share PDF or CSV reports. On-device and private — no account.
Weightings
A, C and Z frequency weighting with a selectable update rate from 200 ms to 10 s.
Spectrum
A live FFT from 20 Hz to 20 kHz with a peak-hold envelope and a peak-frequency readout.
A full acoustics toolkit
Calibration saved per microphone
Run a guided calibration or enter a reference value manually. Results are saved to a named microphone profile, so switching between the built-in mic and an external USB-C microphone does not discard your calibration. A visible input picker always shows which mic is active.
Everything stays on your phone
No account to create, no server to sync to. Your audio recordings, dB readings and noise logs never leave the device unless you choose to export or share them yourself.
Free to use, one-time to unlock
The meter, gauge, spectrum, spectrogram, analyser and dosimeter are free and unlimited. A single one-time purchase unlocks unlimited recording length, full-length video without a watermark, complete dose history and no ads. No subscription, ever. Already bought 'Remove Ads'? You get the full version automatically, at no charge.