I'm looking for an audio effect (on Windows) to add a natural sounding vibrato to a vocal track which has virtually no vibrato.
I don't mean the singer didn't use much vibrato, I mean I have artificially reduced the amount using Melodyne and now I want add a different kind of vibrato.
The reason here is that I have a sample library of female voice samples, but I wanted to extend the range a bit by pitch shifting the lowest and highest samples by up to a few semitones (which, using the original vibrato, still sounds fairly convincing). On a pitch-shifted sample I need to have a different vibrato than the original, otherwise it becomes extremely obvious (artificial sounding) if you play two notes together with the same kind of vibrato.
The vibrato implemented in Auto-Tune is not so great for this purpose; no one sings with a vibrato of a fixed rate like 1Hz or below (I think, if they are not deliberately adding vibrato like in classical singing). I also don't know how to reasonably select different rates for the different samples. Vibrato (after the attack phase) sounds/looks more a like random walk, so ideally I want to find a plugin that realizes something close to that.
Alternatively, I thought about the possibility of using pitch recognition on another vocal track (e.g. one I record myself) to recognize the vibrato and "transfer" it to the sample I need vibrato on. But this is hypothetical, I have no idea whether something like this is even remotely possible.