Recording sounds in a tight space

[David BME]

Hello,

I'm working on a instrument testing system. We have a small instrument that emits beeps and similar sounds, and I need to record the sounds with a microphone and analyze the signals in LabVIEW to verify the instrument is emitting the proper sounds. I would like to be able to embed the microphone in our existing testing chassis because the instrument, which is about the size of a cell phone, sits in the solid-molded chassis cradle with the speaker facing down into the cradle. I think I'm going to need a pretty small microphone because the cradle isn't much bigger than the instrument and is only 3/4" thick or so. I've looked at lots of microphones but none of them seem to be small enough to embed in such a mold. Can anybody suggest a good microphone (and acquisition board, for that matter) for this kind of application? The sounds we want to measure are generally low frequency, probably no more than 10-15 kHz. Noise rejection would be helpful as there are some fans running nearby (although I can probably get that done later in LabVIEW if necessary).

Any advice would be greatly appreciated. Thanks!

David

[RT4CY]

Hi David,

Thanks for posting!  There are many considerations to be made when selecting a microphone (such as dynamic response, sensitivity, temperature range, etc.).  See the following devzone for more information.  Some manufacturers you may want to look into are Shure, Lectrosonics, and Josephson.

On the DAQ side of things, you have many options.  Depending on the complexity of your signal analysis, you may want to consider our Dynamic Signal Acquisition (DSA) cards in conjunction with our Sound and Vibration Toolkit.  DSA should be used if high dynamic range and alias protection are priorities.  Another benefit of our DSA cards is they support IEPE Signal Conditioning (required by many microphones).  I would recommend taking a look at the following hardware.  You also have the option of purchasing the hardware bundled with the Sound and Vibration software.  A big advantage of this software is the Sound & Vibration Assistant.  This includes interactive software for quickly acquiring, analyzing, and logging acoustic data.

NI PCI-4462

NI PCI-4474

NI USB-9233 

NI Sound and Vibration Analysis Software