This is not an answer to your question, but an adjacent thought.
Something we could do now that would have been helpful for the Rosetta Stone is including pictorial representations of the position of the mouth* while pronouncing the words. It’s not important for the meaning, but how cool would it be to know how ancient languages were pronounced? We’re not even totally certain how Latin was pronounced, and that’s both relatively recent and very well represented in the form of Romance languages.
*I began learning German as an adult native speaker of English and this was by far the most helpful thing for my pronunciation. I regularly stealth people on being a non native speaker, so I’d say it works.
This is not an answer to your question, but an adjacent thought.
Something we could do now that would have been helpful for the Rosetta Stone is including pictorial representations of the position of the mouth* while pronouncing the words. It’s not important for the meaning, but how cool would it be to know how ancient languages were pronounced? We’re not even totally certain how Latin was pronounced, and that’s both relatively recent and very well represented in the form of Romance languages.
*I began learning German as an adult native speaker of English and this was by far the most helpful thing for my pronunciation. I regularly stealth people on being a non native speaker, so I’d say it works.