Sadly, it's next to impossible to read the lips of someone that has none in the first place. Starting to panic a little, Frisk looks around nervously.

"Oh no, oh no, um..."

Spotting a pad of paper and a pen laying on a table nearby, Frisk quickly snatches them up and brings them to Papyrus and all but pushes them into his hands.

"Write with this! Your voice went all funny!"