I am looking for a term meaning the use of an angry tone of voice without the raising or lowering of one's volume. Something like yell, but without the implication of raising one's voice.
I'm hoping for something general. Words like snarl and snap don't work in all contexts, so I'm looking for something better.
I'm looking for something that might fill this sentence: "You're ______ again, Dave." as a speaker is counseling a person with anger management issues.