Sound level meter for iPhone
Phon is a sound level meter built like a measurement instrument, not a toy VU meter. Per-model calibration for the built-in microphone, and real calibration files for USB-C measurement microphones like the Dayton Audio iMM-6C.
Requires iOS 17 or later. External microphones need an iPhone with a USB-C port.
Analog needle with mechanical inertia for the eye, precise digital readout for the number. Dark, amber, monospaced.
A, C and Z frequency weightings and Fast, Slow and Impulse time constants, implemented as the standard describes them.
Plug in a USB-C measurement mic, load its calibration file, and Phon applies its measured frequency response and sensitivity.
The built-in microphone is corrected with a per-model offset, so readings are useful before you own any hardware.
Minimum, average, maximum and the equivalent continuous level over the whole session, integrated in energy, not in decibels.
Ten rows per second with timestamps, IEC column names and every calibration detail, ready for a spreadsheet or Python.
The free app measures with A-weighting and Fast time constant. Phon Pro unlocks the rest, once, for every device in your family.
Phon is not a certified Class 1 or Class 2 sound level meter. Built-in microphone readings are approximate. With a calibrated external microphone, accuracy depends on your mic and its calibration file. Do not rely on Phon where a certified instrument is legally required.