How to extract Sound Pressure Level[SPL] data from an audio file(*.wav)

I need to plot frequency[Hz] Vs Sound Pressure Level[pa] from an audio file. I could be able to extract frequency data from the file. I couldn't find a proper solution on how to extract SPL data from an audio file.

The wav file was recorded at a sample rate of 6 kHz.

The microphone has a sensitivity of -58 dB. From that I calculated mic sensitivity to be 1.2589mv/pa. Operating voltage is 4.5V. Impedence is 2.2k ohm. frequency response range of the mic is 100Hz ~ 16kHz

I found this while searching for extracting SPL data,

dB SPL = 20 * log10 { [ (preamp output voltage / voltage gain) / mic's sensitivity] / 20 uPa}

I am not sure whether this one is correct.

Answer 1

[Wayne King]

You cannot do that unless you have some detailed information about how the .wav file was recorded. You need to know how to create the correspondence between voltage and the sound pressure in Pascals.

[Walter Roberson]

This will also require information about the microphone.

[Wayne King]

Exactly! Walter is correct.

[Ramesh Manoharan]

The wav file was recorded at a sample rate of 6 kHz.

The microphone has a sensitivity of -58 dB. From that I calculated mic sensitivity to be 1.2589mv/pa. Operating voltage is 4.5V. Impedence is 2.2k ohm. frequency response range of the mic is 100Hz ~ 16kHz

I found this while searching for extracting SPL data,

dB SPL = 20 * log10 { [ (preamp output voltage / voltage gain) / mic's sensitivity] / 20 uPa}

I am not sure whether this one is correct.

[Muaz Khan]

Can you please specifically mention which information is required about the .wav file recording and the microphone?