Writing a proper audio encoder for HTM, the one that mat did way back on youtube lacked a feature that is present in the cochlea and that would be the “heat map of intensity” of a particular tone.
let me give you a clue of how this might look in a list form:
20hz range: [0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0] - low intensity
20hz range: [0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0] - high intensity
this form of representation is superior to the classic dial thats sort of similar to a dial you would find on a music mix set found on the scalar encoder
This saves the semantic of the tone while embedding the intensity of the tone that can be later used as a location compass in other projects. Unfortunately you would need to use some Fourier transforms for this kind of encoding. I imagine the human (or any other animals) ear uses an aproximator of that kind to represent soundbytes
Also it would be interesting to see results done both using and not using topology