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Sound Level Measurement using Sound and Vibration

I am pretty new to labview and I am making a sound level application using the Sound and Vibration Toolkit.

I am trying out the different VI in "Sound Level" palette and I have hard time figuring out out why "SVL Exp Avg Sound Level VI"

output seems to be always restarting every new acquisition (I mean the chunk of data read in every loop).

 

I read on the documentaion that it restarts the averaging if there is a discontinuity but the data stream looks continuous.

 

Also am I right to assume that the exponential modes on the input of this VI which are "Fast", "Slow" and "Impulse" are analogous to the time weighting on hardware based SLM? If it is then I am assuming that the reading will stabilize if the transducer is presented with a calibration tone.

 

My set-up is using a GRAS microphone connected to a Nexus conditioning amplifier then connected to the line input of an external sound card. I am using a 1Khz tone cvalibrator to verify my  signal.

 

I have attached my sample program for reference.

 

Thank you for the help.

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Hi mervin.mervin,

 

I replaced the sound measurement read VIs in your attached program with a few simulated signals (sine wave, triangle wave) and the Exp Avg Sound Level VI only appeared to restart on every data chunk when I had the "restart averaging" boolean set to True.  Have you compared running this with a True restart value to your normal case to see if perhaps the behavior you're seeing isn't an averaging reset?  If they look identical, then I would guess that there is some discontinuity going on that is causing the reset as you suspected, since the code appears to work fine with a simulated signal.

 

With relation to the exponential modes, your assumption is correct.  There is more detail that should clear up the averaging modes here.  

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