The MR Noise Plug-In from Wave Arts is a broadband noise reduction processor that works in the frequency domain, and requires that the noise spectrum be learned before noise reduction can commence. If your track starts with a bit of silence then this plug-in will work right out of the box, since by default, MR Noise has the Learn parameter enabled. Thus, when you hit Play, MR Noise will learn the noise profile and start noise reduction. The default parameters work well for most cases.
This noise reducing plug-in features an Auto Dynamics mode, which automatically adjusts the attack and release times of the noise reduction processor based on the amount of transients in the input signal. This minimizes artifacts in the noise reduction processing while maintaining sharp transients that would normally be smeared by other methods.
The frequency response display in this plug-in show the spectrum of the input signal, noise floor, and output signal so that you can see at a glance what frequencies are being reduced. The monitor feature allows you to hear the noise that is being removed (with separate volume control). In most cases, you simply have to select a preset and hit Play, and the MR Noise plug-in will learn the floor and start reduction. Then you can simply adjust the Amount control to set the amount of reduction. For fine tweaking, the noise floor and all the reduction parameters can be edited as a function of frequency by dragging control points on the frequency response display.