"well, it seems we are at an impasse."
"so we are. carry on, cat"
"same to you, bird."
"NEITHER OF US CAN EAT THE OTHER SO LET US SAY GOOD DAY"
This is why Rome won so many battles. Enemy spies would wait for them to read battle plans to themselves while mouthing the words; trouble was, they had learned not to!
Spoken language is still processed through the auditory sense and centers. Your brain cannot tell the difference between things you actually hear and things that you have only imagined hearing. Silent reading is imagining the sound of words being spoken. The big question, is what kind of voice do you hear reading the words? (I hear my own voice as it sounded when I was 5.)
^Which is also why if you are close to someone, you often imagine their voices as you read their text messages.