Why Some Family Guy Episodes Sound Diffrerent Than Others

i like eatching family guy. usually i watch it on fox and on comedy central and the voices of each character sounds normal. but when i watch re-run on other channels. the character graphics look bad and their voices sound different. why is that?

let take episode s01/ep06 for example. i watched on cartoon network. the answer is because the voices are translated into diferent languages. so there. thats the answer

unless u can think of a better reason