<p>To understand the estimation of the SoundPressureLevel (SPL) consider that the following notation 60 dB SPL is the same as 60 dB//20uPa-1m (in air).</p>
<p>Assume you have
mic sensitivity -40dBV, that is (94 dB-SPL, or 1Pa results in 0.01Vrms at the microphone output), which means you need a signal of 134 dB-SPL to generate 1Vrms with your microphone</p>
<p>then, say you have measurements of 0.1Vrms, which
correspond to 134-20 = 114 dB-SPL</p>
<p>you may note that the in air dB-SPL is relative to 20 microPascal, while in water the reference is 1 microPascal.</p>
<p>you may also note that the SPL value contains a measurement distance, that is typically 1 m. Now, as you have made your measurements at 1 m, you do not have to correct for the measurement distance. Otherwise you need to correct for spreading loss that is typically 20 log10(R/1m).</p>
<p>Edit: As Brian pointed out, you should take as sensitivity the value given by the manufactorer. I assumed a value (with nice numbers) as OP did not mention a microphone brand.</p>

CC BY-SA 4.0
2024-02-02T00:02:53.477Z
Great answer. Just want to clarify that one would typically measure or estimate the microphone sensitivity rather than make an assumption. Usually this would involve some combination of reading manufacturer's specifications, knowing the exact gain settings, and possibly empirical calibration/validation with a known source.
Brian Miller
CC BY-SA 4.0
2024-02-01T18:23:53.417Z
2024-02-02T07:19:26.623Z
2024-02-02T07:19:26.623Z
WMXZ
<p>I recorded a frog's call at a distance of 1 m, with a Tascam DR40x recorder and its internal microphone.</p>
<p>I want to know if there is a way to calculate what is the SPL in dB of that call or/and the background noise?</p>
<p>I have access to Raven and R.</p>

<r><raven><db><spl>
Is it possible to calculate the SPL of a sound from a wav audio file?
# Is it possible to calculate the SPL of a sound from a wav audio file?

(Asked by: username_0 on 2024-02-01)

I recorded a frog's call at a distance of 1 m, with a Tascam DR40x recorder and its internal microphone.

I want to know if there is a way to calculate what is the SPL in dB of that call or/and the background noise?

I have access to Raven and R.

**Tags:** r, raven, db, spl


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## 1 answers

### Answer by username_1 on 2024-02-01. Score: 2

To understand the estimation of the SoundPressureLevel (SPL) consider that the following notation 60 dB SPL is the same as 60 dB//20uPa-1m (in air).

Assume you have
mic sensitivity -40dBV, that is (94 dB-SPL, or 1Pa results in 0.01Vrms at the microphone output), which means you need a signal of 134 dB-SPL to generate 1Vrms with your microphone

then, say you have measurements of 0.1Vrms, which
correspond to 134-20 = 114 dB-SPL

you may note that the in air dB-SPL is relative to 20 microPascal, while in water the reference is 1 microPascal.

you may also note that the SPL value contains a measurement distance, that is typically 1 m. Now, as you have made your measurements at 1 m, you do not have to correct for the measurement distance. Otherwise you need to correct for spreading loss that is typically 20 log10(R/1m).

Edit: As username_2 pointed out, you should take as sensitivity the value given by the manufactorer. I assumed a value (with nice numbers) as OP did not mention a microphone brand.

> **Comments:**
> **username_2**: Great answer. Just want to clarify that one would typically measure or estimate the microphone sensitivity rather than make an assumption. Usually this would involve some combination of reading manufacturer's specifications, knowing the exact gain settings, and possibly empirical calibration/validation with a known source.  

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