Factutone
A voice that sounds like someone just got a gold star for pointing out your dumb mistake, usually with a side of 'as a matter of fact.'
'As a matter of fact, I didn't just say that, I said it loud and proud.', my teacher, who's never wrong.
'As a matter of fact, I didn't just lose my keys, I lost them in the ocean.', my mom, who lost her keys in the ocean.
'As a matter of fact, I didn't just forget your birthday, I forgot it on purpose.', my friend, who forgot my birthday on purpose.