The switch from aspirate to fricative pronunciations in Greek was between 2-400AD, and was related to ongoing processes in the language unrelated to jaw change.
I'm also skeptical of the only piece of data presented in the article, that it's 29% easier to pronounce these sounds with an overbite. Is that a stable measurement? How much does that speed childhood acquisition of the capacity for these sounds? Percentage of the population that cannot make the sounds at all?
I'm also skeptical of the only piece of data presented in the article, that it's 29% easier to pronounce these sounds with an overbite. Is that a stable measurement? How much does that speed childhood acquisition of the capacity for these sounds? Percentage of the population that cannot make the sounds at all?