In all those ancient monasteries, castles, and graveyards I chatted with spirits in, I didn’t speak to them out loud in English with the intent of having them hear me and understand. Even if it was in England, their dialect would have been so archaic they would not have been able to translate. The point is to form your words so you yourself feel you are clearly expressing your intent. This may or may not be aloud. Either way, the hope is that the spirits can then pick that up from your heart.