I’m looking for a way to shift vocal formants in MetaSound while keeping the fundamental pitch unchanged.
My use case is a planetary atmosphere audio system in Unreal Engine. I want to process voice in a way similar to the helium-voice effect, where the vocal colour/formants change while the fundamental pitch largely remains the same. In other words, I want the voice to sound as if its resonances have shifted, without simply transposing the whole signal.
I know the built-in Pitch Shift node changes pitch and formants together, which is not what I need.
Has anyone found or built a way to do this in MetaSound, either with existing nodes, a filter-bank workaround, or a custom C++ MetaSound DSP node?
I would be interested in any examples, partial implementations, or advice on whether this is realistically achievable inside MetaSound.