The voice we use when we’re pretending to be him talking is that of Pterry from Pee-Wee’s Playhouse. I can’t remember which dog I started that with, but to me all dogs have had that voice since the late ’80s.
When Hank is not around, his speech becomes profanity-laden. E.g. “If someone doesn’t take me for a fucking walk I’m just going to start grabbing shit off the counter. This is fucking bullshit, man.”