Free text being the definition of unstructured data is kind of funny if you think about it (and I agree that amongst computer people that's how they think about it), since the whole point of text is to structure data using alphabets, syllabary or logograms, such that it can be meaningfully be transferred and understood by multiple biological interpreters :)

Those are both examples of signals we can't interpret interfering with the signal we're trying to interpret.

However, it's not like the electrical noise came to be by magic -- it's the result of many interactions that have a structure, and hence impart that structure on the "noise", we just lack key facts to be able to interpret that signal.

Your example of lack of structure, rather than merely something we can't interpret, is algorithmically generated?

I think we may be speaking past each other.