I can make a spectrum for you!
https://www.fiverr.com/share/1EAxbz

This model is a 3D representation of the spectrum of me chanting the five italian vowels in order ( A E I O U ). Just the first 5 kHz of the spectrum are displayed and the amplitude are displayed linearly.
The formants are clearelly visible and so are the harmonics.

The model is not scaled but it's the direct result of the script I've used to generate it, therefore you need to scale. I suggest to scale it evenly in x and y axes and change the z indipendently to have the best result. In Cura you can move down a bit the model, compenetrationg the
horizontal plane, to cut the base if upscaling the z, it become to big.