LabVIEW

[lituslitus]

Does anyone know if there is a VI to do this

I would like to leave a microphone connected to the computer and if there is a noise in the room make a boolean true.

any help is appreciated

[nolsqn]

see the attached VI

the concept is that first use the convert from dynamic data type to a 1d array of samples points to get the min max values when the mic is silent. now use this values as reference , if there is noise it will be out of these values . and a simple comparision to make the boolean true

with regards 

[lituslitus]

Thanks for the quick response and the example VI

when silence, i get values -0.00408936 or -0.0041198

and i get -0.003967 or -0.003936 when the noise event happend

do you think the mic is working OK

thanks

[DFGray · Accepted solution]

That example is only pulling a single value out of essentially a periodic array.  That will give very inconsistent results.  Attached is a VI that may work better for you.  Run it with no sound and a threshold of a couple hundred to get the normal background of your room.  Multiply your background by about 10% or 20% to add a little padding, then set this for the threshold.  Run and it should work.  Since you are looking for an impulse, the analysis is a simple peak-to-peak measurement.  If your background noise lasts very long, you may want to replace this with an RMS measurement to give you more noise immunity.

[lituslitus]

thanks for the response.

I did not have time to try your VI, i will test it tomorrow.

What i am trying to do is to trigger a photo flash when a noise is captured by the mic. i hope your vi works

thank you