Phon: Calibrated SPL Meter

Microphone, decibels & noise

Only for iPhone

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

iPhone

A sound level meter built like an instrument. Per-model calibration for the iPhone mic, and real calibration files for USB-C measurement mics like the Dayton iMM-6C. Phon is a sound level meter built like a measurement instrument, not a toy VU meter. MEASURE • Real-time dB SPL on an analog needle with a precise digital readout • A-weighting and Fast time constant, as defined in IEC 61672 • Session minimum, average and maximum • Per-model calibration for the built-in microphone, so readings mean something out of the box CALIBRATED EXTERNAL MICS Plug in a USB-C measurement microphone and Phon detects it instantly. Load the calibration file that came with your mic and Phon applies its measured frequency response and sensitivity to every reading. Built and tested with the Dayton Audio iMM-6C. Other USB-C measurement mics with an FRD-style calibration file should work too. PHON PRO — ONE-TIME PURCHASE • Calibration file loading for external mics • C and Z frequency weightings • Slow and Impulse time constants • Leq, the equivalent continuous level over the whole session • CSV export of the full session log, with timestamps, IEC 61672 column names and all calibration metadata Family Sharing supported. No subscription, ever.

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Manual calibration. Phon can now be matched to a reference. If you have a sound level meter you trust, or a 94 dB acoustic calibrator, type its level and Phon adjusts its own offset until the two agree. The offset is remembered between sessions and shown under the reading, so you always know what a measurement is based on. The built-in microphone and an external measurement microphone keep separate offsets, so calibrating one never disturbs the other. The offset is recorded in CSV exports too. Measured Phon against a real instrument, or found something odd? I would like to hear about it: support@priet.us

Version 1.0.2

The developer, carlos prieto ortiz, 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.

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    Accessibility

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    Information

    Seller
    carlos prieto ortiz
    Size
    1.5 MB
    Category
    Productivity
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    English
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    © carlos prieto ortiz 2026
  • Privacy Policy

    • More by carlos prieto ortiz

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