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Equalization –
Boost or reduce arbitrary frequencies. You can select one of a
number of different curves designed to equalize the sound of some popular
record manufacturers, or draw your own curve.
Fade In – fades the selection in linearly.
Fade Out –
fades the selection out linearly.
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 -3Db.
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.
