I have recorded and saved a noise wav (named nrp). I appear able to open it but am unable to subtract the noise profile from my subject wav (the "Reduce Noise" option is inoperable.) Any ideas om what I am doing wrong?

After created the noise profile (selecting a range, create noise profile, save noise profile) you are able to load the wav to denoise (or keep the actual one). There you have to load a noise profile first (noise profile/load), or keep the noise profile you created from that audio file, then you are able to remove the noise of it. You have to select first a range of the audio data that should be denoised before the menu option will be activated.