Bug - Hiss Reduction > Capture Noise Floor

[Drew5CC5]

I'm trying to use the Hiss Reduction effect, but when I click Capture Noise Floor only the noise floor for the right channel is captured.

Procedure:

Open stereo audio file in the waveform editor

Activate the Hiss Reduction effect

Select some audio

Click Capture Noise Floor

Only the right channel noise floor is captured, left channel remains flat

I have tried changing the Noise Floor Capture settings in the advanced section of the Hiss Reduction effect. I also tried selecting audio with more noise/sound.

Is this a bug?

Build: 14.2.0.34

Platform: macOS 10.15.7

[SteveG_AudioMasters_]

It might be. Will investigate further.

[Sideras Joan]

I'm having the same problem. Was this ever fix?

[Guest]

Hi to all,

after the last update to Build 22.2 the filter Hiss Reduction it's no more able to capture the Noise Floor.
I guess the same problem that Drew5 has highlighted. I've found this problem on 2 different PC (Windows 10)...

I hope this can be solved soon...

Thank you in advance!

Giovanni

[SteveG_AudioMasters_]

It works fine here - latest build on W10. I have no idea of the situation as far as Macs are concerned. By design it only appears to capture noise from the left or right, but careful observation of the results shows that the effect is applied to both channels. Almost invariably you have to edit the noise floor control until the hiss goes away - this is with a check in the Output Hiss Only box. If you don't do this correctly then it won't work.

[Drew5CC5]

I can confirm that the Hiss Reduction effect is applied to both channels, even though it is only capable of capturing the noise floor from the right channel. I'm now using version 22.2.

I would not say this is by design; it appears to be a bug to me. If the plugin is not capable of capturing a stereo noise floor, then the UI should display a single filter graph instead of one for each channel.

[SteveG_AudioMasters_]

The tool captures a single FFT and applies it to both channels, and you can select whether it's the left or right channel you use to capture the hiss you want to remove:

No, it's not a bug.

[Drew5CC5]

Are you able to capture the noise floor for the left channel? Because I cannot.

[SteveG_AudioMasters_]

Noise selected left channel:

Noise removed:

You will note that it has removed the noise from both channels. It works. If it doesn't work for you, you probably need to do a bit more experimenting with the noise floor setting. Depending upon the nature of the noise you want to remove, you may need to increase the Reduce by slider quite a bit to reveal the correct noise floor setting. Also with hiss, it's generally worth resetting the FFT to a higher value - 8192 works quite well.

[Drew5CC5]

From your screenshot it doesn't look like any noise was captured from the left channel. My results are the same. Capturing the noise floor results in a flat filter graph for the left channel:

Compared to the noise floor captured from the right channel:

This seems buggy to me. I expect the filter graph for the left channel to respond to the Capture Noise Floor action the same as the right channel, but it does not.

[Scott34877586hrqq]

The Hiss Reduction effect is still broken in January 2024 using latest version 24.0.3.3

With some audio selected...

Clicking the Capture Noise Floor" button in the Hiss Reduction effect only sets the control points in the right channel and not the left channel.  If the audio file is a mono channel file the control points never set.

So what ever is set as channel 0 (left) in an audio file, never gets control points set for the noise floor.

I have conformed this on numerous Windows computers of varying configurations.

If I go back and use Audition 2019, the Hiss Reduction effect sets control points on all channels after clicking the Capture Noise Floor" button.

[SteveG_AudioMasters_]

With all due respect, this^ is just not true. If you make a noise selection with the left channel selected, then yes, you will see nothing. But if you now select the right channel, you'll see the noise profile you just created, even though you thought it was from the left. And if you apply it, you'll see it applied to both channels. What's actually 'wrong' is that there's a channel selection at all - it really doesn't need to be there.

What is happening is just the same as happens with process NR. A single FFT profile is created and applied to both channels. If you had a separate one for each channel, whenever there was a difference between one channel and the other there would be a shift in the stereo noise floor, which you wouldn't want. That is why there are only single Noise Floor and  Reduce by sliders, and no splitting.

Yes I agree that the screen layout is, to say the least, a bit confusing. But it is working correctly.