Intensity mapping Vs pressure mapping 1

[elogesh]

Hai,

I need a clarification regarding intensity mapping vs pressure mapping.

We used to carryout the intensity mapping inorder to find out the sound sources.

Due to unavoidable instrumentation problem, our sound laboratory enginner unable to take intensity mapping.But he said he can provide me sound pressure mapping.

Whether it will be any help to me to find the sound sources and directivity of sound?

I thought in intensity measurement, there are both components active and reactive part which help in knowing the quantity of sound energy propagating further away from the near field.But the pressure measurement doesn't account that and more over it is a scalar quantity.

Hence whether pressure mapping will be of any use to me?

Looking forward for your replies.

With Thanks and Regards,
E.Logesh

 

[GregLocock]

Not much, in the near field, and not at all, in the far field.

You might as well use a stethoscope. Seriously.

However, there are other ways.

1) Use an accelerometer and a microphone very close to it. I've never done this but it should give you a very good noise-from-vibration result - sorry no idea on references for it.

2) classic noise from vibration, SEA. Cheers

Greg Locock

 

[ANTOINE]

As greg says : We have tried intensity with a accelerometer and mike close to it and it works.
Holography techniques are based on the acquiisition and separation of both active and recative fields, and are much more accurate in source localization that intensity or pressure.We happen to be specialized in that as we developped hardware and software for this.
Contact : thomas.antoine@metravib.fr

 

[okdb]

Hei Antoine,

Could you explain a little more the holography technique with microphone and accelerometer? I've never heard about that before but it sounds very interesting. I guess one compare the sound signal with the vibration signal and then keep what is in common. A sort of filtering. Am I wrong? Where could I find information on that technique (book, articles,etc.)

Thanks,
OkdB