# Phon: Calibrated SPL Meter — Microphone, decibels & noise

> Microphone, decibels & noise (iPhone/iPad app by carlos prieto ortiz.)

- Source: https://appshunter.io/ios/app/phon-calibrated-spl-meter/id6775261720 (this page in markdown: same URL + `.md`)
- Developer: [carlos prieto ortiz](https://appshunter.io/developer/1889995023)
- Category: Productivity
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 17.0 · 1 MB
- Languages: American English
- Released: 2026-09-22
- Data updated: 2026-10-10

## What is Phon?

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.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Phon App | $14.99 | one-time |


## Is Phon safe?

Not enough ratings yet to assess Phon.

## Is Phon legit?

Phon: Calibrated SPL Meter appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for Phon is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 2 releases)

### 1.0.2 — 2026-09-25

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

### 1.0.1 — 2026-09-22

No release notes.

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All apps by carlos prieto ortiz: https://appshunter.io/developer/1889995023

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-10-10.*