White noise

[jbn]

Hi,

I am new to Audacity. Please forgive me if this is not an appropriate venue for this question.

I would like to create 10 minutes of "white" noise, but only including frequencies above 5KHz. I assume I would want some smoothing of the frequencies between say 4KHz and 5KHz rather than a totally sharp cutoff.

Can such a file be created directly, or can it only be created by filtering a full spectrum white noise signal? I have tried to create the signal by filtering, but I so far have not found a filter (or possibly a set a filter parameters) that does a good job.

Any suggestions are much appreciated.

Thanks,

John

[samspots]

I'm not sure I understand what your problem is.

Try making white noise, then high-passing it at 4000 hz?

[Trebor]

... be created by filtering a full spectrum white noise signal?

Yes that's the way to do it : "Generate" 10 minutes of white noise then apply a high-pass filter using the equalizer, ("equalization")," in "Effect" menu, e.g. ...

white noise after sharpest high-pass filter at 5KHz.wav

(937.54 KiB) Downloaded 63 times

[You could get away with looping white noise after a about a minute: IMO no-one will notice it's repeating]

... so far have not found a filter (or possibly a set a filter parameters) that does a good job.

5KHz sharp high-pass filter 'curve' drawn in Audacity equalizer.png (27.83 KiB) Viewed 560 times