How does a .wav audio file being filtered

I’m currently making a thesis about a vocal minimizer plug-in, to be embedded
in the the Effect menu.

Right now I’m having a hard time understanding how a .wav file(or any music file being open or imported in Audacity)
being filtered using the Audacity’s filter function (when we program the vocal minimizer plug-in we make use of the
filter function available in the Audacity)…
but I couldn’t exactly understand what does it filter or the details behind its process.

I hope someone will explain or give me some resources
where I can see the process flow when Audacity perform the function Filter…


Sorry, I can’t make sense of your question. If you get no other replies, you may want to try rewording your question.

I guess my words are not that understandable…Sorry

If that’s the case, can someone kindly explain to me what
really happens when an audio file is being open or imported in the Audacity?

how does an audio being processed, when you apply a certain effect to it?

This is my initial Architectural design of our Vocal Minimizer Plug-in…
where I couldn’t explain the filter part…
That’s why my Prof. said it is some kind of broad, that’s why I must be detailed in how
the audio file is being filtered before it is being passed/applied the vocal minimizer effect.

first : Recorded Audio Input (The audio file being open or imported in Audacity)
Then being filtered by: DSP Filter
third: The Filtered Audio Input enters in our Vocal Minimizer Plug-in
Lastly:the Modified Audio file being applied with the vocal minimized…


A link maybe or any resources about audio processing in the Audacity will do…

It would help me a lot, if someone will kindly explain to me somehow
how audio is filtered with Filter function in the Audacity …Please!


AFAIK a WAV file is not filtered when it is imported Audacity. Audcacity reads in the WAV file and converts it into an Audacity Project. Note carefully that an Audacity is not a file but rather a collection of files:

  1. a top level master project file called <project_name>.aup
  2. a folder at the same filing level called <project_name>_data
  3. and within the folder a sub-folder structure with lots of little .au files - segments of the recording (mainly audio clips - but a couple of then are graphics files)

When you re-open a project with Audacity you should always open the <project_name>.aup top level file. This tells Audacity how to thread together all the little .au files. It is deliberately designed this way so that Audacity doesn’t have to open and work with a single humungously large file, which would hamper performance. You should not be attempting to open or manipulate any individual .au files.

WAV files and Audacity projects are both “lossless” and uncompresssed formats.

If you leave Audacity set to its default 32-bit floating setting and export to 16-bit -then on downsampling for the export Audacity will apply a process known as dithering - see this Wiki article:


I’m really confused, about the question I posted days ago…Now, I kinda
understand a little about what happen to the
file opened or imported in the Audacity…
Sorry for my confusing question…

If the file is converted to .aup file then if you use the filter function of the Audacity
what actually is being done or filtered?..

Thanks a lot!


What I’m trying to say, is that how does the filter function provided by
the nyquist programming language really works not the filter function in Audacity…

I’m sorry that my question is confusing…
If someone will help me I would gladly thankful…

The filter functions in Nyquist, such as the low-pass, high-pass and notch filters are based on a biquad filter: