High Pitched Whining Whilst Recording

[flynwill]

As Trebor observed that noise is actually quite a bit different from the usual USB data lines interference, particularly with the shifting in pitch that is going on. I suspect it may have a different origin.

[Trebor]

Copying and pasting that code into the Nyquist prompt hasn't changed anything by the sound of it ...

After posting the code into Nyquist prompt, you then have to apply Nyquist prompt to the audio as if it was an Effect,
i.e. select the audio you want to process, then apply Nyquist prompt.

[kozikowski]

If it's shifting pitch, then the notches aren't going to work. The news just keeps getting better...

Koz

[Trebor]

If it's shifting pitch, then the notches aren't going to work ...

No shifting-pitch within MrSeeb's audio , but the ratio of the harmonics present changes with time ...

MrSeeb's audio.png (338.81 KiB) Viewed 1172 times

Maybe an artefact of Pulse Width Modulation of the power supply ? ...

The resulting spectra (of the three cases) are similar, and each contains a dc component, a base sideband containing the modulating signal and phase modulated carriers at each harmonic of the frequency of the pulse.

http://en.wikipedia.org/wiki/Pulse-width_modulation

[MrSeeb]

Copying and pasting that code into the Nyquist prompt hasn't changed anything by the sound of it ...

After posting the code into Nyquist prompt, you then have to apply Nyquist prompt to the audio as if it was an Effect,
i.e. select the audio you want to process, then apply Nyquist prompt.

I select the track, giving it a yellow outline, and then go through effect > Nyquist Prompt > C/P the code > then click OK. I've also tried highlighting the track and repeating but to no avail. I couldn't apologise more if I am doing this completely wrong, unfortunately software such as this is not my forte.

Thanks for all the help everyone, it really means alot.

[kozikowski]

Well. That should have worked...

??

You can select a track by clicking just above MUTE.

Koz

[MrSeeb]

Well. That should have worked...

??

You can select a track by clicking just above MUTE.

Koz

I've tried to upload a .mp4 to show me doing it but the attachment adder isn't happy with that and keeps deleting it, so I'll give you a detailed run down of what I do. After opening the file, I click just above mute to select the audio track, darkening the selected area, I then go to effect, and click Nyquist Prompt, then copy and paste the text into the blank area. After this I click OK, nothing else and then play back the track and it hasn't changed. Sorry about the lack of ease on this, I imagine this is getting quite annoying!

[kozikowski]

I imagine this is getting quite annoying!

Puzzling, more like it. Hang in while we figure out what to do.
Koz

[kozikowski]

"Good" news! It doesn't work for me, either.

Must be a typo in the code or some other programming damage. We need someone who can read Nyquist to figure it out.

Koz

[Trebor]

I select the track, giving it a yellow outline, and then go through effect > Nyquist Prompt > C/P the code > then click OK. I've also tried highlighting the track and repeating but to no avail.

That sounds like you're doing the right thing ...

[ changing to from waveform-view to spectrogram-view is not necessary to apply the effect,
spectrogram-view just conspicuously shows the consequence of applying the code]

audio-gif2.gif (469.58 KiB) Viewed 1158 times

NB: the whine removal code I posted is specific to the audio you posted. It won't remove any old whine,
only the whine produced by the particular apparatus you used to make the audio you posted.

"Good" news! It doesn't work for me, either. Must be a typo in the code or some other programming damage. We need someone who can read Nyquist to figure it out.

I'm using an old copy of Audacity : 2.0.6 , [on Windows]. If you're using a different version that may explain why it isn't working for you, i.e. possibly a bug in a later version of Audacity, (if the Nyquist code is being copied & pasted accurately).