2015-03-06

Golden Eyes: Experiments with Audio - Part 4 (I think I saw some noise!)

note: you can read part 1, part 2, and part 3.

Hi again,

In this part I will show another processing on our audio. Let's look at a kick drum waveform for the processed track D and compare it with our original:

Operation D

What do you see? Can you spot some difference? Perhaps if we could see the difference:

Whispering?

The difference is really minimum but there is definitely something there! This kick audio has some high frequencies in there and that makes it difficult to analyze. Below is a zoomed in part of the bass track and its processed version.

..or you have shaky hands!

Now it is easy to see that some low amplitude, high frequency and random looking data has been added in the processing. Here they are overlaid for comparison (click the image for a bigger version). Smooth red line is the original waveform while the blue jagged line riding on top of it is the modified one.

Overlay of process D

This type of effect is most probably some type of high frequency noise (or hissing) riding below our audio. Let's really amplify the difference track:

The portrait of a noise

Yes, it really looks like high-pass white noise here. In fact, I had put some high-passed noise generator plugin to get this effect.

What about when we listen? Well, the noise has been clearly heard and correctly identified as such when listened; especially when compared with the original audio. Many times some sort of tape hiss is deliberately added to tracks to get a more organic or vintage feel and it can be quite pleasant when used correctly. In fact many analog-mimicking VST plugins will just do that for the analog effect.

Hope you enjoyed that. In the next part, let's degrade the sound and see what happens!

Cagil

Continue with part 5.





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