Decibel Dossier: Sound Meter

Noise level meter & dB report

Only for iPhone

Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.

iPhone

Prove a noise problem. Measure it, log every incident, and export a tamper-proof report anyone can verify by scanning its signature - for noise complaints & disputes. Decibel Dossier turns your iPhone into a sound level meter that not only measures noise, but records it and produces a verifiable report. Measure Real-time sound pressure level in dB(A) and dB(C), with Leq (equivalent level), max/min, L10/L90 statistics, a live spectrum and a time history. Hearing safety Your reading is compared against NIOSH and OSHA occupational-noise references: a hazard level (safe / moderate / hazardous) and the recommended safe exposure time at the current level (for example, about 8 hours at 85 dBA, halving every 3 dB). A quick reference chart shows how the level compares to everyday sounds. Report Generate a structured PDF report containing the measurement details, capture device and calibration status, statistics, the hearing-safety assessment, and a disclaimer. Each report carries a digital-signature QR code, so anyone receiving it can scan and confirm the key fields have not been altered. Records Every measurement is saved on your device. Review history, add the location and noise source, and export at any time. Privacy Measurement, statistics and reports are all processed on your device. The microphone audio is converted to a sound level in real time and discarded; no recordings are stored, nothing is uploaded, and there is no account. Free to measure; exporting a watermark-free report requires a one-time purchase (a single report or a lifetime unlock). Note: this is a consumer measurement tool. A phone microphone is not a certified measuring instrument, and readings depend on the device, environment and how you hold it. Results are for reference and are not a legal or occupational-health determination. For a measurement with legal standing, use a calibrated Type 1/2 sound level meter or a qualified professional. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

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Now available in Spanish, Portuguese, German, French, Japanese and Russian. Search improvements and minor fixes.

Version 1.0.4

The developer, 秋林 周, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    • 秋林 周
    Size
    • 2.7 MB
    Category
    • Utilities
    Compatibility
    Requires iOS 16.0 or later.
    • iPhone
      Requires iOS 16.0 or later.
    • Mac
      Requires macOS 13.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • English and Simplified Chinese
    Age Rating
    4+
    In-App Purchases
    Yes
    • Monthly membership $4.99
    • Yearly membership $19.99
    • Lifetime unlock $39.99
    • One report $2.99
    • Learn More
    Copyright
    • © 2026 Qiulin Zhou
  • Privacy Policy

    • More by 秋林 周

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