Lost her voice?

Hi! Me again.

My kitten is relatively silent, but I know she has a very soft adn sweet voice. So when she is hungry she will use it a lot, however, after she ate and is ready to snuggle up, she will mover her mouth into a meow, but with no tone coming out....
How can that be? She will meow again when she is hungry....

i dunno. my female kitten does the same thing and she's almost six months old. when i first brought her home i noticed her doing the "silent meow" and at first thought she was hissing at me.
she does meow but more often she is either silent or she makes kind of a squeaking sound. her brother on the other hand is a real talker.