Audition has a NR tool built into the app. I do not know of a plugin by them (usable in another app, that is).
Free options are often Audacity (application) or ReaFIR (plugin). Not "great," but adequate in some cases.
Depending how extensive this is, there are posts regarding Audition 3 (from Adobe CS2), which can be gotten for free, but still seems to have the same NR algorithm which I use. You can add it to SONAR's Utility Menu for "one-off usage," but also run it stand alone to perform batch functions on truckloads of files at the same time (format conversion, macros, etc.).
Best start is to try ReaFIR, and if the number you need to do is a "lot," consider a batch alternative (especially if these all exhibit similar/identical issues).
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Quick Edit: Found
the post which I had followed to check AA3 out initially. When I checked it (when that post was made), the installation process links you to the Adobe servers, which then issue a complete set of Creative Suite 2 (CS2) registration numbers, i.e., all applications which were released with CS2 (c. 2006).
post edited by mettelus - July 05, 16 5:08 AM