I have 'raw' audio files recorded from an iPhone 12 Pro Max. I'd like to convert the raw 16 bit .wav amplitude to SPL. It's been a while since I was doing this kind of stuff hands-on and I was never an expert, but I think what I need to know is 1) the ADC input range and 2) the microphone sensitivity (mv/Pa). Are these known? Or perhaps has someone just measured with a reference system? People obviously know how to get dB SPL from phones somehow to make sound level meter apps.

This answer suggests that it may not be possible to recover SPL due to automatic gain control, but I'm told that this file was recorded without any processing (filtering etc.) which I assume includes gain control.

  • $\begingroup$ A sound file can't have an SPL, there is absolutely no correlation. $\endgroup$
    – Tetsujin
    Commented Jul 14, 2021 at 15:35
  • $\begingroup$ @Tetsujin My terminology is probably sloppy. At each point in time, there is an air pressure value at the microphone diaphragm, which is converted to a voltage by the transducer, which is converted to a 16 bit value by the ADC. I have the 16 bit values, and I want the air pressure values. $\endgroup$
    – Evan
    Commented Jul 14, 2021 at 22:09


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