He's not? Someone taught him how to use the device, right? He didn't accidentally turn the sound off or anything?

[Look, it happened to him, okay. It'd make sense to him if it happened to another version of himself, too. These things are hard to figure out and learn!]

Try going over again now? He might have just not felt like answering his door. Sometimes it's a real bother to get up out of bed when you're hung over, you know?