Noise on/off button: Enable or disable the noise oscillator.
Noise pop-up menu and field: Choose a noise waveform. These have different spectral characteristics that can be further refined with filters. You can step through the available waveforms with the Previous and Next buttons (the arrows).
(Noise) Vol knob: Set the output level of the noise oscillator. When multiple elements are used in a source, use this control to set the relative level of the noise component.
Tune knob: Set the tuning of the noise signal.
Low Cut knob: Set a low cutoff frequency for the noise oscillator. All frequencies above this value are allowed to pass. All frequencies below are attenuated.
High Cut knob: Set a high cutoff frequency for the noise oscillator. All frequencies below this value are allowed to pass. All frequencies above are attenuated.
The Low Cut and High Cut parameters work in conjunction with each other to act as a bandpass filter, where the noise signal that falls within the two cutoff ranges is allowed to pass.
Download the guides:
Logic Pro User Guide: PDF