Problem is I can't find a section that is the buzz only...everything has at least a little crowd noise...even getting the quietest part as my Profile makes it sound pretty hollow when appllied to the whole WAV.
What s/w are you using? If CEP/Audition, check out the Help file. There's some good info there about setting FFT, applying NR multiple times at low percentages vs. one big application at 100%, tweaking the NR profile manually, etc. IME, takes
lots of trial and error and don't expect to remove the sound outright - only hope to minimize it.
Unfortunately, I can't listen to the sample on my work laptop, but...maybe a notch filter will help? No idea as I haven't heard the buzz, but...might be worth checking out.