Can Acoustic Holography be conducted using LabView?

[sanchhat]

I am in the process of building a small anechoic chamber, with the help of a peer, to do acoustic measurement for our senior project in college. We will be using a array of microphones (4x4) to map out sound intensity along a planar surface of a single side of a sound source within the chamber. The array of mics and chamber or small in scale given the fact that this project will end up being a small scale lab perform by students in an engineering measurement course offered at our college. Anyway, we need to determine the software needed to perform such a measurement. We are currently looking into LabView but are unsure whether or not LabView by itself is sufficent or if the "Sound and Vibration Measurement" add-on is required since we will need to get dB and frequnecy readouts from each microphone simultaneously. Any suggestions. Hardware recommendations are also welcome. Thanks.

[chrisger]

hello,

first of all: when using 16 microphones at the same time i suggest to use a 16 or 32 channel DAQ - card and connect each mic to a channel. otherwise i wouldn't know how to acquire the signals synchronously (even at a time scale of ms). you will need a acquisition rate of about 50 kS/s for each channel.

if you manage to connect the mics to the DAQ-card the acquisition of the 16 channels and formatting of the data as wav-files will be no problem at all.

to calculate some spectras, acoustic power, applying windows and filters etc. the build in LabView VIs are sufficient for that (but you need the LabView "Full Development" or "Professional" distribution). if you wan't to create a STFT you will need the "Sound and Analysis" Toolkit, or you write it by yourself.

i don't recommend the built in LabView sound capture vis for acquiring data from a sound card device! the cpu load gets ~90% at just one single channel (P4 1.7 GHz, 512 MB), and the vi takes twice as long to execute as the acquisition.

best regards and good luck with your project
chris