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FFT Filter - Similar to Equalization, lets you enhance or reduce arbitrary
frequencies. The curve here uses a linear scale for frequency.
Invert - Flips the waveform vertically, the same as a phase inversion in the
analogue domain.
Noise Removal - This effect lets you clean up noise from a recording. First,
select a small piece of audio that is silent except for the noise, select
"Noise Removal", and click on the "Get Noise Profile" button. Then select
all of the audio you want filtered select "Noise Removal" again, and click
the "Remove Noise" button. You can experiment with the slider to try to
remove more or less noise. It is normal for Noise Removal to result in
some distortion. It works best when the audio signal is much louder than
the noise.
Normalize - Allows you to correct for DC offset (a vertical displacement of
the track) and/or amplify such that the maximum amplitude is a fixed
amount, -3 dB. It's useful to normalize all of your tracks before mixing. If
you have a lot of tracks, you may then need to use the track gain sliders to
turn some down.
Nyquist Prompt - For advanced users only. Allows you to express
arbitrary transormations using a powerful functional programming language.
See the Nyquist section of the Audacity website for more information.
Phaser - The name "Phaser" comes from "Phase Shifter", because it
works by combining phase-shifted signals with the original signal. The
movement of the phase-shifted signals is controlled using a Low
Frequency Oscillator (LFO).
Repeat - Repeats the selection a certain number of times. This operation
is quite fast and space-efficient, so it is practical to use it to create nearly-
infinite loops.
Reverse - This effect reverses the selected audio temporally; after the
effect the end of the audio will be heard first and the beginning last.
Wahwah - Uses a moving bandpass filter to create its sound. A low
frequency oscillator (LFO) is used to control the movement of the filter
throughout the frequency spectrum. Adjusts the phase of the left and right
channels when given a stereo selection, so that the effect seems to travel
across the speakers.
