Effects Reference

142 Chapter 12 Specialized
For example, if the noise floor of your recording is very high (more than –68 dB),
reducing it to a level of –83 to –78 dB should be sufficient, provided this does not
introduce any audible side effects. This effectively reduces the noise by more than
10 dB, to less than half of the original (noise) volume.
 Noise Type slider and field: Set to a value appropriate to the type of noise you want
to reduce.
 A value of 0 equals white noise (equal frequency distribution).
 Positive values change the noise type to pink noise (harmonic noise; greater
bass response).
 Negative values change the noise type to blue noise (hiss—tape noise).
 Smoothing Frequency knob: Adjusts how smoothing is applied to neighboring
frequencies. If the Denoiser recognizes that only noise is present on a certain
frequency band, the higher you set the Frequency Smoothing parameter, the more it
changes the neighboring frequency bands to avoid glass noise.
 Smoothing Time knob: Sets the time required by the Denoiser to reach (or release)
maximum reduction. This is the simplest form of smoothing.
 Smoothing Transition knob: Adjusts how smoothing is applied to neighboring volume
levels. If the Denoiser recognizes that only noise is present in a certain volume range,
the higher you set the Transition Smoothing parameter, the more it also changes
similar level values to avoid glass noise.
 Graphic display: Shows how the lowest volume levels of your audio material (which
should be mostly or entirely noise) are reduced. Changes to parameters are instantly
reflected here.
Using the Denoiser
Locate a section of the audio where only noise is audible, and set the Threshold value
so that only signals at, or below, this level are filtered out. Then start playback and set
the Reduce value as you listen to the audio, so that as much noise as possible is
reduced, but as little of the desired signal is reduced.
The Denoiser uses Fast Fourier Transform (FFT) analysis to recognize frequency bands
of lower volume and less complex harmonic structure, and then reduces them to the
desired dB level. In principle, this method is completely discrete, as neighboring
frequencies are also affected.
If you use the Denoiser too aggressively, however, the algorithm will produce artifacts,
such as glass noise, which are obviously artificial and therefore less desirable than the
existing noise in most cases. If using the Denoiser produces these artifacts, you can use
the three Smoothing knobs to reduce or eliminate them.