About the silent meow
I learned something new today: the silent meow isn't silent!!
From 101 Questions Your Cat Would Ask Its Vet If Your Cat Could Talk by Bruce Fogle
Cats have a hearing range, and a meow range, that is beyond the hearing range of humans. When a cat utters a 'silent meow' people don't respond because they just don't hear it. If they see the cat meow, they are enchanted and think the silent meow has been performed especially for them. They don't understand that the meow is silent only because their hearing is so limited. It is a perfectly good meow to any other cat.