Apertness

And in general, the Freedom or Apertneſs and vigour of pronuncing (as is particularly obſerved in the Bocca Romana) and giving ſomevvhat more of Aſpiration; And on the other ſide, the cloſeneſs and Mufling, and (as I may ſay) Lazineſs of ſpeaking […] render the ſound of their Speech conſiderably different, though they all ſhould uſe the ſame Alphabet.