Anybody else notice how that Scottish male reference voice sounds considerably more English in the synthesized versions.
It was that and the Swedish-accented English ("Sentence in Different Voices" section, middle recording) made it struggle. No traces of the Scandi-lilt were left in the synth version.
Final note would be the French speaker at the bottom of the page seems to be English first language, despite having very good spoken French. Not quite as pure a test of that last part as I'd have liked, despite the ability for the speaker to perhaps read the synthesized version in English back in English. That could be fun.
However, I'm not convinced at all by these voice transfers across language. I can imagine the second Chinese one being the same speaker in both languages, but not the three others.
Even struggles to finish the sentence due to the effort of reading in the 2nd to last one. Struggles with an extremely common word, 'grand', as well as stumbling over a simple sentence. To be fair, he has heard enough French (i.e. lived and studied there most likely) to get the intonations mostly right but there are a few other giveaways too... it's just not natural or native from where I'm sitting.