How to remove noise background from an edited track

Hello all.
I have edited a track with 3 different tones (3 different voices).
The problem is that while listening to this modified track, in the background, the transition from one tone to another is clearly audible.
I tried to remove the background noise (with a lowering of the voices volume) but if I amplify back the track, this ‘transition’ is still there (and, therefore, the track sounds as being clearly modified).
I’d like to know if there is any chance to have this track as more harmonized and realistic as possible.

Do you mean that you can hear a change in the background “room noise”?
If so, the proper solution is to record each part in a very quiet room so that the “room noise” is quiet enough to not be noticeable. This is the main reason why people record in recoding studios. Unfortunately, once the recordings have been made, if there is a noticeable amount of background noise, then there is not much that you can do about that.

If the background noise is fairly quiet and is a constant noise (such as “hiss”), then it may be possible to make the background noise less obtrusive by using “Noise Reduction” (
Note that noise reduction cannot help with removing background “sounds” such as other people talking, or traffic noise, or a TV in the background…

No no… I do not mean this. What I mean is that I recorded a track [3 voices, mine - the one of my mom - the one of my sister]. I then changed the ‘pitch’ of all 3 voices [by going to “Effect” >> “Change Pitch”] but this procedure also affected the background under each voice [that is, it’s okay that while one listens to the track, he/she hards the different pitch of the spoken language… but he/she also heards the transition in the background from one pitch to another].
At the end: how I can keep the bacground at the same pitch even if I changed the pitch of the 3 voices (this means: I do not want the background to have 3 different pitches - the 3 applied to the voices).
Do you see what I mean?