Because it was developed independently, it looks like no other.
This function, which was created little by little over a long period of time, is a product of the developer's hobby, and the only reference code is the Freeier transform algorithm called FFT. It is what was given.
Therefore, if used strictly for voice analysis, it is likely to be inaccurate.
Currently, my priority is to be able to perform it easily, and my main focus is on visually observing which pitches are being played strongly.
The sound analyzer has various options, but these are not necessary for some kind of spectrum analyzer, but they were branched out during the development process and left as settings, so some items are currently not very important. There are many and they are complicated.