"Rakes in the money by feigning illness. Amazed at his daughter's schemes." 

He stands outside with his daughter selling MP candies, the main item to restore MP in the game. The way they do this is with him pretending to be sick, and his daughter guilt tripping the poor soul who interacted with them into buying it...for over 5 times its normal selling price. A lot of his voice lines are just...coughing. For most of his speaking lines, he breaks character. This is because he and his daughter either made a sale or during the moments after the protagonist returns their faces when they get stolen.

I imagine his voice to be in a medium-medium low range because of his age. It's implied that he's at least middle age because he has a daughter, but because she's so young, I don't think he's a senior. Since I imagine this isn't their first day doing this due to the daughter's comment, "we finally sold one, dad," he was probably feigning illness for a while. So I imagine his voice has gotten a little raspier over the days!