Active noise cancellation (using a PC with a sound card).

[Vameanu]

It is my first project using Labview and I'm... terrified. 😄 I must must achive a segnificant attenuation of the noise in a closed volume using some NI devices (I only get to chose them after I manage to achive some results on the PC). So, my first problem:

I managed to aquire sound using my microphone, but I don't know how to sample it. (I get to read it only as blocks through the device buffer).

[Ben]

"I must must achive a segnificant attenuation of the noise in a closed volume using some NI devices ..."

At first glance I would say "probably can be done using an FPGA as a target" since the FPGA can close a very fast loop.

But to do that with a microphone input on a PC running Windows...

I suspect that would be an exercise in futility.

Anyone out there been able to turn around a microphone input fast enough to something like this?

Ben

[johnsold]

I agree with Ben that you are not likely to achieve good results with a desktop OS and standard hardware.

What you might be able to do is to acquire the noise, calculate the cancellation, and display it along with the original - delayed by an amount necessary to allow for the acquisition and analysis. If this shows the potential for good cancellation, then use the data to determine how fast the hardware and computations need to be to achieve noise cancellation which would be perceptible to a human. In other words do a feasibility study with simple hardware and software to show what needs to be done.

Lynn