Denoiser eliminates or reduces any noise below a threshold volume level. It does this by using Fast Fourier Transform (FFT) analysis to identify frequency bands of lower volume and less complex harmonic structure, which it then reduces to the defined decibel level.
If you use Denoiser too aggressively, you may encounter artifacts that are less pleasant than the existing noise. Use the three Smoothing knobs to reduce or eliminate these artifacts. See Denoiser smoothing parameters.
Threshold slider and field: Set the threshold level to a point below which the noise signals are reduced.
Locate a section of the audio where only noise is audible, then set the Threshold slider to a dB value that filters only signals at or below this level.
Reduce slider and field: Set the amount of noise reduction applied to signals that fall below the threshold. Aim for a Reduce slider value with which noise reduction is optimal but little of the music or vocal signal is reduced. Each 6 dB reduction halves the volume level, and each 6 dB increase doubles it.
Note: If the noise level of your recording is very high (more than −68 dB), reducing it to a level of −83 to −78 dB should suffice, provided no audible side effects are introduced. This reduces the noise by more than 10 dB, to less than half its original volume.
Noise Type slider and field: Determine 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—hissy tape noise.
Graphic display: Shows how the lowest volume level signals in your audio material, which are mostly or entirely noise, are reduced.