I can bray,make a pigeon and crow sounds,crickets and Coucal sounds
By “transform” if you mean the vocals,
For the gecko thingy I make a side smile so a tiny dimple gap forms at the edge of the lip, and I push air out so as the pressure builds up it opens, closes, opens, closes, and it trills.
For the Cuckoo one, I just make an “oooo” sound with saliva in my mouth, sort of vibrate my throat to make the trill. I actually have trouble describing it.
If you mean turning recordings into sonograms,
I use an mobile app called “Aspect Pro”.
This is packed with humour ;) 
Welcome to the forum!
I can also mimic the sound of a Hyena
welcome to the forum @ miacomet
Thats great that u know some part of the Owl calls,not everyone has the capability to mimic it
It says, “I’m sure those grapes are sour anyway.”
I doubt it would convince actual crows, but people say I do all of the fish crow calls convincingly, including both their more relaxed calls and the more agitated, “scolding” call.
I didn’t start doing the calls to interact with the crows, but rather, to communicate to inexperienced birders how to tell the difference between fish crows and American crows. I feel like I was getting “good” when someone could hear my imitations and the reaction was: “Oh yeah, that sound, I have heard that and just didn’t know it was a different species of crow!”
I was even successful impressing a purple sunbird(male) he was flying all around me trying to find that female, he never give up but I stopped chirping, this time I fooled the bird :). Now I use this technique to record bird calls and it is successful
I’ve had some luck calling back and forth with a whippoorwill, but it has to be far enough away that they can’t tell that my throat clicks have some distinctly nonavaian elements!
American Bittern is also a fun one to try, and fail miserably at!
I also can do a Barred Owl well enough that they respond to me. A friend who is a wildlife rehabber had an unreleasable Barred Owl who almost jumped me when I called at his cage door. She had had him for years, and he considered her his “mate” and would land on her head and try to mate with her.