Calculate LEQ in full and 1/3 octaves

[R_ATS]

I have been tasked to calculate Leq in full and 1/3 octaves from my pressure traces I have already measured.

I have found the VI to calculate the Leq final number from my pressure trace.

Thanks Rohan

[dsb@NI]

When you are ready for us to help, please post a clear question and the relevant part of the code. 

[R_ATS]

Doug,

I do not have any code at the moment as I cannot find any details that LabVIEW can calculate Leq in octaves.

I already have a program that will give me a single Leq number from my test measurements.

The engineer who has tasked me wanted the Leq results in octaves like you are able to get from B&K sound level meters.

Rohan

[GerdW]

Hi Rohan,

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@R_ATS wrote:

I have been tasked to calculate Leq in full and 1/3 octaves from my pressure traces I have already measured.

I have found the VI to calculate the Leq final number from my pressure trace.

---

What's the problem when you already "found the VI to calculate the Leq"?

When starting a thread in a public forum with a very specific question it often helps to provide as much information as possible!

• What is "Leq"? Why don't you provide an explanation or a link to a website doing so?
• Do you know the formula to calculate Leq?
• Where are you stuck?
• Which errors do you encounter?

[billko]

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@GerdW wrote:

Hi Rohan,

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@R_ATS wrote:

I have been tasked to calculate Leq in full and 1/3 octaves from my pressure traces I have already measured.

I have found the VI to calculate the Leq final number from my pressure trace.

---

What's the problem when you already "found the VI to calculate the Leq"?

When starting a thread in a public forum with a very specific question it often helps to provide as much information as possible!

• What is "Leq"? Why don't you provide an explanation or a link to a website doing so?
• Do you know the formula to calculate Leq?
• Where are you stuck?
• Which errors do you encounter?

---

Sometimes users are so busy describing the issue they forget to ask the question.

[dsb@NI]

If you have access to the Sound and Vibration Toolkit, you can use the fractional octave VIs to calculate band power in each octave. Use linear averaging in the octave VIs, and then take the square root of the band power to get the equivalent level.

[Bob_Schor]

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@GerdW wrote:

• What is "Leq"? Why don't you provide an explanation or a link to a website doing so?
• Do you know the formula to calculate Leq?

Leq is a interesting (and fairly obscure) measure of "equivalent continuous sound level" that seems to require sampling (ambient?) sound/noise over an extended period of time and doing a particular kind of averaging of sound energy .  Finding a cogent description of what this is and the proper way to measure/quantitate this probably requires someone trained in acoustics, perhaps from a standpoint of "noise exposure".  I don't have an algorithm (and haven't seen one) to calculate this quantity.

Bob Schor

[GerdW]

Hi Bob,

thanks for explanations.

I already found out about Leq on my own using Google and this (German) website - it also shows some formulas and graphs…

My point to the OP: when you ask questions for very specific problems you should (atleast) explain all the abbrevations you use in your question!

[dsb@NI]

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I do not have any code at the moment as I cannot find any details that LabVIEW can calculate Leq in octaves.

I already have a program that will give me a single Leq number from my test measurements.

The engineer who has tasked me wanted the Leq results in octaves like you are able to get from B&K sound level meters.

Hopefully, this snippet gets you started. The snippet does use Sound and Vibration Toolkit VIs. 

[R_ATS]

Thank you.

I will have to get a copy of LabVIEW 2020 as some of these features are not in 2018.

Yesterday I recorded some sound pressure levels using a B&K sound level meter and had its DC output going into my data acquisition so now I have a recorded sound pressure trace i pascals that I can process in LabVIEW and the LZeq 1/3 octaves that have been calculated in the B&K SLM, which will allow me to check my results.