One of the antagonists in my plot is a kenku scientist. The party has met her a couple of times and is more and more disturbed with her experiments. She had accepted her curse and the fact that she cannot speak of her own accord. So she makes the best of it and studies the speech of others, with a special focus on the sounds of different dangerous creatures.
The party will face off against her and I plan to use a plethora of harmful sounds in this fight (utilizing the kenku’s mimicry trait), for example a harpy’s Luring Song, a gibbering mouther’s Gibbering and a banshee’s Wail. Now I would like to know, if this would actually work the way I want. (Which means, that the party would have to make saving throws against those abilities). I know, that I can do whatever I want as a GM and that my word is law. But I’d like to keep things logical and consistent, and I’m not sure if these imitated sounds would have the desired effect. I have some arguments for it and against it.
Does a sound mimicked by a kenku have the same effect as the real sound?
(I know that according to the rules, they cannot copy features from other creatures with their mimicry. Otherwise it would say so. This question is more focused on whether this would make sense in an in-universe context).