Narrowband Noise

This is intended to be a replacement for the old “Noise Band” effect (which does not work

I’ve posted it here for testing / checking and proofreading the GUI text.

New features in this version:

  • Error checking user input.
  • Duration allows fractional values with one slider rather than 2.
  • Amplitude may be specified by the user.
  • Supports independent L/R channels for stereo tracks.
  • GUI updated to current conventions.

noiseband.ny (1.8 KB)
The latest version is available here:

Maybe the comments should have ;; per convention.

So people can use it from the Generate menu without changing defaults, I suggest “Identical” (renamed as “Mono/Dual Mono” or similar) be default.


Yes, no problem. The license statement had just been copied from an older plug-in. I’ll update it, Also I think that I prefer the comment block above the ;control lines so I’ll change that too.

“Dual Mono”? Is that different from “stereo”?

I’m happy to change the wording of “Independent / Identical” but I think that “Mono / Dual Mono” is a bit confusing. Any other ideas?

Thanks for the feedback .

How about
Number of audio channels: “1” or “2 (stereo)”
default = 1

That wording ties in with the (Nyquist) error message “Nyquist returned too many audio channels”.
noiseband.ny (1.85 KB)

I believe identical left and right channels in a stereo track is properly described as “dual mono”, but anyway, for those who have a stereo track to begin with, isn’t choosing “1” audio channels and getting two channels (or four if you have two stereo tracks) more confusing than before? I agree it’s a bit less confusing now if you have a mono track and choose “1”.

Maybe you could have

A) “Number of independent channels” 1, 2


B) “Independent channels:” No, Yes (needs stereo)

You could have “different” instead of “independent”.

I think A) is better than what we have now (if you don’t mind the length of the label).

I think progress labels for effects are un-necessary as you know, but as we have them, should line 7 be

;action "Generating Narrowband Noise..."

to distinguish it from Audacity’s Noise Generator?

line 30 has a UK English spelling of “Centre” while the others are “Center”:

(setq err "Centre Frequency out of range.~%"))

line 33 has “Band Width” in the error but “Bandwidth” (more correct?) is in the GUI:

(setq err (strcat err "Band Width out of range.~%"))) l33

I noticed the errors don’t display the user’s incorrect input value as in other plug-ins, but “~%”.

Is the default length long enough? I would expect this to be of some value for brainwave entrainers? If they are the main marked, they will want minutes and seconds, I’d have thought.


That’s what I would call it, but not sure how obvious that would be.

Well for a stereo track, choosing “1” does return 1 audio channel and Audacity puts it into both left and right of the stereo track (but I agree that isn’t obvious either).

For multiple tracks “Identical” channels creates 1 channel per track whether mono or stereo tracks.
For multiple tracks “Independent” creates 2 channels for a stereo track and an error message for mono tracks.

I’m quite tempted to remove the “stereo” feature. If someone really wants stereo they can generate to mono tracks and join them together. That would certainly be a lot more simple. It’s a shame that Nyquist does not know if the track is mono or stereo.

It could be, but it already says “Narrowband Noise” at the top of the window, so I went for the brief description.

Spelling a word just one way shows a lack of imagination :wink:
This is the last time that I use the word “center” as a variable, it caused loads of trouble while writing the code :smiley:

Yes, “bandwidth” I think is correct (or at least, more common).

I don’t think that it’s necessary to show the actual values, but “~%” should have been “n” (except for line 50).

If the max length is too long, then we (yet again) run into the memory problem when normalizing.
Also, it makes it quite fiddly to set a short duration with the slider.
The original effect had a maximum slider duration of 30 seconds, whereas this version has a slider range of 60 seconds.
I’d not considered brainwave entrainers. What would you consider to be a reasonable maximum?

I could remove the “stereo” option and add a “minutes” slider.
1 hour mono uses about 600 MB of RAM. For independent stereo it would be double (but for 2 mono tracks, still 600 MB).
I can add a progress bar, but it will not appear until Nyquist has completed the number crunching, which could be quite a while when generating a very long track.

If I’m right that brainwave entrainers and sound effects lovers will like this, I don’t think you should rip real stereo out. Stereo makes a lot of difference to the “effect” of these sounds.

If you don’t like suggestion A) or B) for text, how about

“Stereo Output” No, Yes

with a custom instead of generic error message if they say “yes” with only a mono track?

20 or 30 minutes?

A “minutes” slider might be OK ; it would be still be nice to support fractional seconds.

I think the [minutes] [seconds] text input box in Click Track works OK, but would I assume supporting other than integers in such a box is hard to code?


I like “Stereo Output: [No, Yes]” best. It’s simple and clear imo.
Unfortunately I cannot intercept the default message because Nyquist generator plug-ins do not know how many channels there are in the track. The generic error message is produced by Audacity when it receives the audio data back from Nyquist and tries to put it back into the track.

I think that the best that I can do is to output some debug information to the debug screen (which only appears if the user clicks the Debug button rather than the OK button). This is not an ideal solution, but at least it would an easy way to troubleshoot the error. The plug-in could output to the debug window what user options were set and how many audio channels were returned.

I’ll go for two sliders:
minutes (integer): default = 0
seconds (float): default = 30.0 (same as built in generators)

There should be no problem with up to 20 minutes.

The only drawback with supporting fractional seconds is how to support 59.99 seconds. To support fractional seconds greater than 59 seconds, the slider range for seconds needs to be 0 to 60. Three sliders (minutes, seconds, milliseconds) seems like overkill.

The problem is commas.

I think this version implements all of the issues raised.
noiseband.ny (2.17 KB)

Thanks, Steve.

I think it would look better (and balance the label lengths better) if you wrote out “minutes” and “seconds”

;control dur-m "Duration (minutes)" int "" 0 0 20
;control dur-s "Duration (seconds)" real "" 30 0 60

Very nice, I think.



Unless anyone spots any other issues, this is the version that I’ll upload to the Audacity wiki.
noiseband.ny (2.18 KB)

The latest version of the Narrowband Noise plug-in is available on the wiki:

If I want to generate noise made of frequencies between 30 and 100 Hz, do I specify 65 Hz as the center and 70 as the bandwidth?

Have you tried that?
Did give you what you wanted?