IEC 61672-1 weighting via Accelerate vDSP, calibrated per iPhone model.
Lossless AAC stays on device under File Protection: Complete. Never uploaded.
Optional GPS fix is matched to the nearest of 16 city noise ordinances bundled in the app.
5-page evidence pack with a SHA-256 chain-of-custody footer and a `.sha256` sidecar.
Live dB meter, 3 recordings/month (5-minute cap), Verify PDF.
Unlimited recordings, evidence PDFs, GPS, sealed mode, ordinance comparisons. 7-day free trial.
Adds background trigger sentinel, iCloud sync, multi-event bundle PDFs, dispute templates. 14-day free trial.
NSFileProtectionComplete.Each recording feeds an AVAudioEngine input tap into a 2048-point Hann-windowed FFT (Accelerate vDSP). The spectrum is A-weighted, RMS becomes SPL, and the per-iPhone calibration table corrects offset and slope. Every 100 ms, NoiseProof writes a sample of (t, dB(A), peak frequency, vibration magnitude). The audio file is hashed with SHA-256 and the digest is embedded in the evidence PDF and stored alongside as a .sha256 sidecar.
U.S. recording laws vary by state. Several states require all parties to consent before private conversations may be recorded. NoiseProof shows a dedicated warning on first launch and on the last page of every evidence PDF. The app does not give legal advice. Consult a licensed attorney.