DeNoise does not work with recordings from Zoom H5 Recorder
If I record from my microphone direct to audacity and export the file as a WAV 24 bit file then I can import to Adobe Premiere and use the De-Noise feature and it works great.
If I record audio from my Zoom H5 field recorder in a 48khz 24bit format (and any other format) and drop that audio file into Premiere (after copying to my local folder) the DeNoise feature does nothing. It does not show any background noise at all. It is unable to detect anything or make any changes whatsoever.
This is the file made from Zoom H5:
This is the file made using Zoom H5 recording directly into Audacity and exported as a WAV 24bit file
If you put the 1st file into premiere you cannot use the DeNoise filter. It wont do anything
If you put hte 2nd file into premiere you can add DeNoise and it works great.
Please look into this. I can provide more file examples if needed. Note that it does not matter what format I record with in Zoom. 48khz 24 bit / 16 bit / MP3 / Etc. If a recording is made with Zoom, copied to PC, then added to a project the DeNoise will not work. It detects no background noise.
You should really figure out why your Zoom recording is inverting the polarity of one of your channels when recording stereo. This will fix it at the source, you will keep running into strange errors like this since it as essentially a malformed file, and true stereo recording will almost never cancel each other out like what you are experiencing here.
And, Audacity doesn't have this issue cause it isn't introducing a polarity reversal when recording. For some reason it is fine.
Also, you will see this same issue with the DeReverb effect, and with the Multiband Compressor, as well as other effects also. This should really be fixed at the source, in your Zoom recorder.
How to fix this. The fix inside Premiere is relatively easy, and there are three ways to fix just thinking off the top of my head, you just need to flip the polarity of one of the channels of the audio. Premiere has a tools to do that easily.
Add an instance of the Channel Mixer effect to the clip. Then drag it to the top spot of the Effects Control panel so it is right underneath the Channel Mixer effect. This will place it in the top most spot in what is called the "Signal Chain" and all effects below this will be affected by the the Channel Mixer effect.
Next, open the Channel Mixer effect by pressing the Edit button. In the dialog that open, in the "L" tab under Input channel, next to the "L" slider, put a check in the "Invert" box. Then add the DeNoise after and it will work.
Alternatively, instead of using the Channel Mixer effect, use the "Fill Left with Right" or Fill Right with Left" effect in the top spot of the Effects Control panel. It will have a similar effect as above.
Lastly. since the audio is actually mono (it is the same information on two channels of a stereo file, even if one is polarity reversed), right click on the source file and select 'Audio Channels'. In the dialog that opens, uncheck the "R" channel and hit ok. Then add an instance of the DeNoise effect and it should work.
Ah, really interesting find here. I think I can explain what is going on.
Your Zoom file has the polarity of one of the channels reversed (this is also commonly called the "phase", it means the phase of the two channels are exactly 180 degrees from each other). Probably it is in the wiring of when you are recording or some internal setting in the recorder. This means that if you sum the two channels together they will completely cancel each other out. You can hear this summing cancelation if you add an instance of the Channel Mixer effects and use the preset "All Channel 50%". The two channels will sum to mono, and perfectly cancel each other out. You wont hear anything. All the energy from the left channel is canceling out all of the energy in the right channel, so no energy is going to the speakers.
So, why does the effect not work in this case. Internally, the effect is split into various parts that serve different functions. One of them is the noise detection section. The noise detection sums to mono so that noise is removed from all channels. So when your file have a polarity inversion in one channel (as yours does), the summing of the audio inside the effects that is sent to the detection circuit has zero energy. So the effects appears as if it is not doing any detection at all. That is why it looks like it isn't working. It is working, but the detection portions is hearing nothing.