I really appreciated the portrayal of the main character's stutter in Stephen King's IT. It's just... there. There's a moment at the end where he makes a big speech before the third act and his friend goes "wow... he didn't stutter once" which felt very authentic. Back on point though, you could try things like: * Needing to cancel social plans because they needed to talk a lot during the day, and now they're out of verbal communication energy * Not being able to reliably use Siri or Alexa * Generally opting for live webchats rather than phone calls when talking to services or businesses * Biting their mouth a lot (just me?!) * Blocking in a way that's funny (e.g. I tend to block when saying 'country' and it comes out as 'cunt') * Someone on the phone thinking the line is bad when it's not I dunno, just some ideas. Good luck!