Interesting excerpt:
De Boer agrees that our brains are the bottleneck. But, he says, instead of being limited by how quickly we can process information by listening, we’re likely limited by how quickly we can gather our thoughts. That’s because, he says, the average person can listen to audio recordings sped up to about 120%—and still have no problems with comprehension. “It really seems that the bottleneck is in putting the ideas together.”
I linked the paper in the OP. Check page 7 - it shows the formulae they’re using.
I’ll illustrate the simpler one. Let’s say your language allows five syllables, with the following probabilities:
If you apply the first formula, here’s what you get:
Of course, natural languages allow way more than just five syllables, so the actual number will be way higher than that. Also, since some syllables are more likely to appear after other syllables, you need the second formula - for example if your first syllable is “sand” the second one might be “wich” or “ing”, but odds are it won’t be “dog” (a sanddog? Messiest of the puppies. Still a good boy.)
ASCII is extremely redundant - it uses 8 bits per letter, but if you’re handling up to 32 graphemes then 5 bits is enough. And some letters won’t even add information to the word, for example if I show you the word “d*gh*us*” you can correctly guess it’s “doghouse”, even if the ⟨o⟩'s and the ⟨e⟩ are missing.