In the post-episode vignette Mazin said he decided to make Sam deaf as a way to make him especially reliant to Henry for survival. Sam/Henry are sort of a parallel father/child relationship to Joel/Ellie.
Mazin, you made Sam "especially reliant" on Henry by aging him down from 13 to 8. Now he's a lil kid who's basically wholly dependant on his big brother, unlike the dynamic in the Joel and Ellie parallel.
However, If you peep some of the shots in the tunnels, you'll notice that Henry has Sam walking behind him most of the time, damn near ignored. That's a no-no. I know you need Joel and Ellie's help but there's no way you letting your deaf lil bro outta ur sight like that. He shoulda been walking right next to Henry or right in front of him if he's gonna be "especially reliant" on him. I was watching those scenes like
Making him deaf is a way to ratchet up the tension and accomplish what Mazin claimed. It also allows you to be more inclusive, which the games are renowned for. Typically, we get the black character also being a pole smoker. Mazin chose to make the black character a deaf boy. But in this instance, I'm not mad at it cuz it was more emotional and lil Kevionn killed it.
Kevionn was outstanding. Nico Parker was outstanding in episode 1. They were the best acted children characters in their respective episodes. It's a goddamn shame they both had to die.
God damn you, Ellie, for not staying awake with Sam like you said you would and making Henry have to put his own brother down. That's why you "sorry."